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Introduction to Momentum | Forces and Motion | High School Physics | Khan Academy

Video vocabulary

about

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US / ə'baʊt /

UK / əˈbaʊt /

A1
  • adverb
  • To be ready to; going to
  • Nearly; approximately; roughly
  • Near; next to; close to
  • In every direction; in the area of
  • preposition
  • Concerning or of (a topic)

ground

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US / graʊnd /

UK / ɡraʊnd /

A1
  • noun
  • Connection of electrical equipment to earth
  • Place where people play particular sports
  • Solid surface of the earth that we stand on
  • verb
  • To break (coffee, etc.) into tiny bits with machine
  • To make loud jarring noise by pressing hard
  • To make sharp or smooth through friction
  • To press together with force making a sound
  • To punish someone by not allowing them to go out
  • To hit the bottom
  • (Of boat) to hit the bottom so it cannot move
  • To prevent a plane from taking off
  • To place the ball over the goal line in rugby

get

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US / ɡet /

UK / ɡɛt /

A1
  • verb
  • To become affected by illness or disease
  • To begin to feel or understand an emotion or idea
  • To send or bring someone or something home, etc.
  • To go somewhere to obtain something
  • To (cause to) do a particular thing
  • To obtain, receive or be given something
  • To currently have
  • To prepare for use
  • To understand something being said or read

what

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US / wɒt /

UK / hwɑt, hwʌt, wɔt, wʌt,hwət, wət /

A1
  • pronoun
  • Thing or things that; the same kind as
  • Used to emphasize something you are about to say
  • adjecitve
  • Used to refer to a particular amount, or number
  • Used to place emphasis on a particular quality
  • adverb
  • To a certain degree
  • determiner
  • Question words used for asking for information
  • exclamation
  • Used to express excitement, shock, or surprise
  • Used to ask people to repeat something they said

language

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US / ˈlæŋgwɪdʒ /

UK / ˈlæŋɡwɪdʒ /

A1
  • noun
  • Words or signs used to communicate messages

like

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US / laɪk /

UK / laɪk /

A1
  • adjecitve
  • Being equal in status or kind to something else
  • Similar; the same
  • adverb
  • For example
  • preposition
  • Used as a filler; used to ad emphasis
  • In a way similar to the way something is done
  • Such as; for example
  • verb
  • To want to
  • To find something pleasing; to prefer something

interesting

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US / ˈɪntrəstɪŋ /

UK / ˈɪntrɪstɪŋ, -tərɪstɪŋ, -təˌrɛstɪŋ /

A1
  • adjecitve
  • Taking your attention; making you want to know
  • verb
  • To make someone want to know about something
  • To persuade to do, become involved with something

hard

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US / hɑ:d /

UK / hɑː(r)d /

A1
  • adjecitve
  • Difficult to do; difficult to understand
  • (Of facts) not able to be misunderstood; clear
  • (Of alcohol) strong
  • Involving or requiring lots of work, effort, care
  • Being full of pain, trouble, and problems
  • Strong
  • (Of edge) clear; sharp
  • Difficult to bend, break or cut; solid
  • adverb
  • With lots of force, power, or impact

seconds

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US / 'sekəndz /

UK / 'sekəndz /

A1
  • other
  • Units of time; one sixtieth of a minute
  • Short periods of time you wait for someone
  • verb
  • To agree to support a proposal at a meeting

essentially

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US / ɪˈsenʃəli /

UK / ɪˈsenʃəli /

A2
  • adverb
  • Basically; (said when stating the basic facts)

roughly

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US / ˈrʌfli /

UK / ˈrʌflɪ /

B1
  • adverb
  • Approximately; (of numbers) about; around
  • In a manner that is violent or not careful
  • In an inexact, imprecise or violent way
  • In a basic, simple manner

second

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US / 'sekənd /

UK / ˈsɛkənd /

A1
  • adjecitve
  • 2nd; the one following first
  • noun
  • Unit of time; one sixtieth of a minute
  • Short period of time that you wait for someone
  • (Do) soon

mean

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US / mi:n /

UK / min /

A1
  • adjecitve
  • Being good at
  • Nasty; unkind
  • Not liking to spend money; cheap; stingy
  • noun
  • Average of a set of numbers
  • verb
  • To express a particular idea or thought
  • To intend to do something in particular
  • To have a particular meaning or value

right

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US / raɪt /

UK / raɪt /

A1
  • adjecitve
  • Correct or true
  • The south side of you looking at the rising sun
  • adverb
  • Exactly in a place or time
  • Being appropriate for a particular event
  • In a straight or direct manner
  • noun
  • Something you are legally or morally allowed to do
  • Ideal of what is just and good
  • Political view based on conservatism
  • verb
  • To fix something previously wrong or unjust
  • To make upright, as a boat that has turned over

quantify

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US / ˈkwɒntɪfaɪ /

UK / ˈkwɑ:ntɪfaɪ /

B2
  • verb
  • To find or calculate the quantity of something

people

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US / 'pi:pl /

UK / ˈpipəl /

A1
  • noun
  • Persons sharing culture, country, background, etc.
  • Men, Women, Children

then

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US / ðen /

UK / ðɛn /

A1
  • adverb
  • A time that is not now
  • Following another thing in time or arrangement
  • Following on reasonably from what was just stated
  • At that time, not now

emerge

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US / ɪ'mɜ:dʒ /

UK / ɪˈmɚdʒ /

A2
  • verb
  • To rise or appear out of some background

different

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US / ˈdɪfrənt /

UK / ˈdɪfrənt /

A1
  • adjecitve
  • Not of the same kind; unlike other things

each

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US / i:tʃ /

UK / itʃ /

A1
  • determiner
  • Every one of two or more things
  • pronoun
  • Per one person or thing

that

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US / ðæt /

UK / ðæt, ðət /

A1
  • adjecitve
  • The person or thing being talked about
  • Used to identify something both the speakers know
  • adverb
  • Used to reinforce adjectives and adverbs
  • To such a degree
  • conjunction
  • Used to connect a noun clause
  • Used to introduce an adverbial clause
  • Used to introduce a noun clause
  • determiner
  • Used as a noun to refer to something
  • pronoun
  • Referring an object far away
  • Used to refer to the relative pronoun ‘which’

physic

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US / 'fɪzɪk /

UK / 'fɪzɪk /

A1
  • noun
  • (Archaic) medicine causing evacuation of the bowels

zeros

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US / ˈzɪərəʊz /

UK / ˈzɪroʊz /

A1
  • other
  • Numbers meaning none; 0
  • verb
  • To set a scale or other device to show 0

tell

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US / tel /

UK / tɛl /

A1
  • verb
  • To (strongly) advise a person to do something
  • To be able to guess
  • To say or communicate information to someone
  • To inform, but without speaking; indicate
  • To have a negative effect on someone
  • To order someone to do something; command
  • To recognize something based on certain signs
  • To report something to an authority
  • To explain something or teach someone something

try

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US / traɪ /

UK / traɪ /

A1
  • noun
  • Act of putting the ball over the rugby goal line
  • verb
  • To make an effort, to attempt to do something
  • To examine someone or something in a court of law
  • To test to see if it is good or you like it
  • To make a person go through hardship; test
  • To examine something to see if it works

will

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US / wɪl /

UK / wɪl /

A1
  • noun
  • Desire or choice of someone
  • Document saying who gets your money when you die
  • Strong desire to do something; determination
  • Desire to do something; strong wish to do
  • other
  • Used with verbs to express the future
  • verb
  • To leave property to someone after your death
  • To use mental effort to make something happen
  • Am (is, are) likely to do
  • To influence someone to do something
  • To make something happen by strongly wanting it

while

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US / waɪl /

UK / hwaɪl, waɪl /

A1
  • conjunction
  • In spite of the fact that; although
  • During the time that; at the same time
  • noun
  • Short amount of time

use

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US / ju:s /

UK / ju:s /

A1
  • noun
  • Ability to employ something
  • Need to enable it to work
  • Permission to do something with something
  • Act of spending money
  • Operation of a machine for its function
  • verb
  • To have; to eat, drink, consume etc.
  • To need to operate or work
  • To operate a machine, e.g. a computer
  • To treat a person badly
  • To do something with, for a task or purpose

either

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US / ˈaɪðə(r) /

UK / ˈiðɚ, ˈaɪðɚ /

A1
  • adjecitve
  • One of two (used when there is a choice of two)
  • adverb
  • (After negative statements) likewise, in addition
  • conjunction
  • Used as the first of two connected things
  • determiner
  • Used as the first of two connected things
  • pronoun
  • The one or the other

imagine

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US / ɪ'mædʒɪn /

UK / ɪˈmædʒɪn /

A1
  • verb
  • To think creatively about; form mental picture of

sort

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US / sɔ:t /

UK / sɔrt /

A1
  • noun
  • Group or class of similar things or people
  • verb
  • To organize things by putting them into groups
  • To deal with things in an organized way

here

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US / hɪə(r) /

UK / hɪr /

A1
  • adverb
  • In this place; at this location, position or time

convention

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US / kənˈvenʃn /

UK / kənˈvɛnʃən /

A2
  • adjecitve
  • Concerning a large formal assembly or meeting
  • noun
  • Official agreement between two or more countries
  • Large formal assembly, e.g. to make laws
  • Proper and widely accepted way of behaving

probably

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US / ˈprɒbəbli /

UK / ˈprɑbəbli /

A1
  • adverb
  • That is likely to happen or be true

dimension

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US / daɪˈmenʃn /

UK / dɪˈmɛnʃən, daɪ- /

B1
  • noun
  • Number of planes (X, Y, Z axes) an object has
  • Measurement in space, e.g. length or diameter
  • Scope, extent or size of something abstract

guess

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US / ɡes /

UK / ɡɛs /

A1
  • noun
  • Answer given when you don't know if it is correct
  • verb
  • To give an answer without knowing if it is correct

certain

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US / ˈsə:tn /

UK / ˈsɚtn /

A1
  • adjecitve
  • Definite, fixed
  • Referring to an unspecified amount or quantity
  • Being sure about something; without doubt

intuition

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US / ˌɪntjuˈɪʃn /

UK / ˌɪntuˈɪʃən, -tju- /

B2
  • noun
  • Natural ability to guess or feel things

four

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US / fɔ:(r) /

UK / fɔr, for /

A1
  • number
  • 4

many

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US / 'menɪ /

UK / ˈmɛni /

A1
  • determiner
  • Used to refer a large number of things

once

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US / wʌns /

UK / wʌns /

A1
  • adverb
  • One time; one instance
  • At a time in the past
  • conjunction
  • When; as soon as

actually

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US / ˈæktʃuəli /

UK / ˈæktʃuəli /

A1
  • adverb
  • Used to add new (often different) information

notion

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US / ˈnəuʃən /

UK / ˈnoʃən /

B1
  • noun
  • Sudden idea or desire to do something

physics

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US / ˈfɪzɪks /

UK / ˈfɪzɪks /

A1
  • other
  • The study of heat, light, and energy on objects

maybe

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US / ˈmeɪbi /

UK / ˈmebi /

A1
  • adverb
  • Possibly but not certainly; perhaps

zero

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US / ˈzɪərəʊ /

UK / ˈzɪroʊ /

A1
  • noun
  • Temperature when water turns to ice
  • number
  • Number 0
  • verb
  • To set a scale or other device to show 0

good

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US / ɡʊd /

UK / ɡʊd /

A1
  • adjecitve
  • Proper, appropriate or right
  • (Of an amount) enough; plenty
  • Excellent; high quality
  • Acting well or properly; of moral character
  • In a positive or happy emotional state
  • noun
  • Advantage or benefit

now

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US / naʊ /

UK / naʊ /

A1
  • adverb
  • At the present time or moment
  • Right away or in the next possible moment
  • Used to refer to something that just happened
  • Time between the present and a moment in the past
  • conjunction
  • Resulting from or because of something

really

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US / ˈri:əli /

UK / ˈriəˌli, ˈrili /

A1
  • adverb
  • Used to stress something that is said; definitely
  • In a true or accurate manner
  • Very

same

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US / seɪm /

UK / sem /

A1
  • adjecitve
  • Being equal in quality and amount
  • Identical; not different
  • Not changing; constant

give

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US / ɡɪv /

UK / ɡɪv /

A1
  • noun
  • Degree of flexibility in something, a material
  • verb
  • To hand over or present something to someone
  • To cause someone to have or experience something

definition

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US / ˌdefɪˈnɪʃn /

UK / ˌdɛfəˈnɪʃən /

A2
  • noun
  • Explanation of word's meaning, as in dictionaries
  • The sharpness of an image on a screen
  • Visual clearness in a photo or on a screen

can

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US / kæn /

UK / kən,kæn /

A1
  • noun
  • A metal container for storing food
  • other
  • Able to; have the skill to; have the time to
  • verb
  • To have permission to
  • To be possible to do
  • To preserve food by sealing it in a metal container

equal

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US / 'i:kwəl /

UK / ˈikwəl /

A1
  • adjecitve
  • Same in shape, size, or number
  • verb
  • To add up or be the same as

but

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US / bət /

UK / bʌt,bət /

A1
  • conjunction
  • Used before you say something different, opposite

star

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US / stɑ:(r) /

UK / stɑr /

A1
  • noun
  • Very famous person, usually an entertainer
  • Someone who does something very well
  • Your horoscope
  • A bright planet of hot gas in the night sky
  • A 5-6 sided asterisk-shape
  • verb
  • To perform or play a main role in a movie, play
  • To do something very well
  • To mark with a 5-6 sided asterisk-shape

would

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US / wʊd /

UK / wʊd /

A1
  • other
  • Used to indicate something imagined
  • Used to ask or request something politely
  • Verb used to indicate possibility, request etc.
  • Used to indicate a preference
  • Used to indicate a reaction
  • Indicates something that occurred repeatedly
  • Used to indicate willingness or ability to do

want

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US / wɔnt /

UK / wɑnt, wɔnt /

A1
  • noun
  • Something you desire or wish for
  • State or condition of poverty
  • verb
  • To desire or wish for something; hope for a thing

formula

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US / 'fɔ:mjələ /

UK / ˈfɔrmjələ /

A2
  • noun
  • A mathematical or scientific rule
  • Plan, rule or method for doing or making something

video

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US / 'vɪdɪəʊ /

UK / ˈvɪdiˌo /

A2
  • adjecitve
  • Of a moving film, with sound
  • noun
  • Recording capturing action with sound
  • verb
  • To make a moving film of, with sound

pick

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US / pɪk /

UK / pɪk /

A1
  • noun
  • Sharp tool used for breaking the ground
  • Item selected from a group of choices
  • verb
  • To take fruit or vegetables from a plant or tree
  • To decide on a thing from various choices; select
  • To remove (flower, etc.) with your fingers

not

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US / nɒt /

UK / nɑt /

A1
  • adverb
  • Word indicating the negative
  • (Used to form the negative of verbs)

vector

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US / 'vektə(r) /

UK / ˈvɛktɚ /

B2
  • noun
  • Math a quantity that has both size and direction

business

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US / ˈbɪznəs /

UK / ˈbɪznɪs /

A1
  • noun
  • A company formed for making profit
  • Matter that has to be dealt with; task; situation
  • Activity of working to make a profit

this

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US / ðɪs /

UK / ðɪs /

A1
  • adjecitve
  • Used to indicate something already been discussed
  • Used to indicate something happening around now
  • adverb
  • An indication by a physical motion or gesture
  • A specific amount of
  • determiner
  • Person, thing, or idea near you
  • pronoun
  • Person, thing that has already been discussed

five

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US / faɪv /

UK / faɪv /

A1
  • number
  • 5

how

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US / haʊ /

UK / haʊ /

A1
  • adjecitve
  • To what degree? in what amount?
  • adverb
  • (Used to explain the way to do something)
  • exclamation
  • For what purpose or reason?
  • (Used to ask someone or something's condition)

the

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US / ðə /

UK / ðə /

A1
  • article
  • Used to refer to something already mentioned
  • Used to show there is only one of something
  • determiner
  • Used to describe all of a family

also

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US / 'ɔ:lsəʊ /

UK / ˈɔlso /

A1
  • adverb
  • In addition; too; in a similar way

stress

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US / stres /

UK / strɛs /

A2
  • noun
  • Emphasis on part of a word or sentence
  • Pressure on something or someone
  • A state of mental tension, worry due to problems
  • verb
  • To emphasize one or more parts of a word, sentence
  • To put pressure on something or someone
  • To say your opinion strongly
  • To be in a state of mental tension due to problems

answer

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US / 'ɑ:nsə(r) /

UK / ˈænsɚ /

A1
  • noun
  • Reply to a question someone asks
  • Solution to a problem or test question
  • verb
  • To reply to a question someone asks
  • To solve a test question or a problem

truck

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US / trʌk /

UK / trʌk /

A2
  • noun
  • Homegrown vegetables and fruit for sale
  • Large vehicle suitable for transporting things
  • Simple frame with wheels for moving things; cart
  • verb
  • To transport something on a lorry, van

relative

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US / ˈrelətɪv /

UK / ˈrɛlətɪv /

A2
  • adjecitve
  • Measured or considered in comparison to another
  • (Grammar) referring to words that appear earlier
  • noun
  • Members of the family
  • Humans or animals sharing the same family history

you

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US / jʊ /

UK / ju /

A1
  • pronoun
  • Person someone is speaking or writing to
  • Person or people in general

little

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US / 'lɪtl /

UK / ˈlɪtl /

A1
  • adjecitve
  • Being short in length of time
  • Not great in size, amount, or degree; small
  • Being very young or younger than others
  • adverb
  • By an amount or degree that is not very much
  • Not often; rarely
  • noun
  • A person's name

able

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US / 'eɪbl /

UK / ˈebəl /

A2
  • adjecitve
  • Skilled; good at something
  • Having the ability to do something

three

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US / θri: /

UK / θri /

A1
  • number
  • Number 3

stand

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US / stænd /

UK / stænd /

A1
  • noun
  • Effort to fight against something
  • Piece of furniture; device to hold or support
  • Place in a stadium where spectators watch
  • Table where things are sold at a fair or market
  • verb
  • To be a candidate in an election
  • To be able to accept someone, something; bear
  • To last for a long time
  • To be upright; not be sitting or lying down
  • To place something in a particular position; place
  • To be (as stated)
  • To still be valid
  • To have an opinion about something

than

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US / ðən /

UK / ðən /

A1
  • conjunction
  • Used to compare two things that are not equal

let

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US / let /

UK / lɛt /

A1
  • verb
  • To allow someone to do something
  • Introducing a suggestion to do something together
  • To rent a house, etc. to others

rock

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US / rɒk /

UK / rɑk /

A1
  • noun
  • Type of popular music with a strong, loud beat
  • Strong, tough person who can be relied upon
  • Big stone; hard, solid substance forming mountains
  • verb
  • To be greatly upset by something, e.g. a death
  • To be extremely effective or pleasing
  • To play, sing along with, or dance to heavy music
  • To move back and forth or from side to side

make

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US / meɪk /

UK / mek /

A1
  • noun
  • Product made by a particular company; brand
  • verb
  • To arrange or prepare something e.g. dinner
  • To get to (a place) on time
  • To gain the status of (teacher, lawyer, etc.)
  • To create something by putting things together
  • To earn a certain amount of money at a job
  • To cause or force a person to do something
  • To cause something to happen or be formed

big

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US / bɪɡ /

UK / bɪɡ /

A1
  • adjecitve
  • Popular
  • Serious
  • Large

magnitude

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US / ˈmægnɪtju:d /

UK / ˈmæɡnɪˌtud, -ˌtjud /

B2
  • noun
  • Number representing force of an earthquake
  • Size or importance
  • Number representing the brightness of a star

one

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US / wʌn /

UK / wʌn /

A1
  • pronoun
  • You; we; people in general; someone
  • The thing or person previously referred to
  • adjecitve
  • Used to refer to people generally
  • Being a strong example of (something mentioned)
  • number
  • Number 1

other

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US / 'ʌðə(r) /

UK / ˈʌðər /

A1
  • adjecitve
  • A thing different from that mentioned
  • determiner
  • (Something) else; not the first (one)
  • pronoun
  • Being the one and only thing of that category

negative

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US / 'neɡətɪv /

UK / ˈnɛɡətɪv /

A2
  • adjecitve
  • Being harmful, unwanted or unhelpful
  • In mathematics, being less than zero
  • Focusing on the bad aspects; pessimistic
  • noun
  • The opposite to a positive electrical charge
  • In grammar, containing words such as 'no' or 'not'
  • Reply to a question or statement that means 'no'
  • Image on camera film used to make a photo

unit

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US / ˈju:nɪt /

UK / ˈjunɪt /

B2
  • noun
  • One apartment in a building
  • Group of people, e.g. soldiers, that work together
  • A chapter of a textbook
  • A standard of measurement of something
  • Single item made by a company

with

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US / wɪð /

UK / wɪð, wɪθ /

A1
  • preposition
  • As an employee of a certain company
  • Against something or someone
  • By using something as a means
  • Due to; because of
  • Including
  • Possessing as a feature
  • Related to
  • (Of the manner/attitude by which you do something)
  • Used to express that people or things are together

car

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US / kɑ:(r) /

UK / kɑr /

A1
  • noun
  • A vehicle with wheels and engine to carry people

calculate

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US / 'kælkjʊleɪt /

UK / ˈkælkjəˌlet /

B2
  • verb
  • To find an answer using mathematics
  • To make an educated guess about something

clear

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US / klɪə(r) /

UK / klɪr /

A1
  • adjecitve
  • Empty; without anything in it or on it
  • Being certain and without doubt
  • Being without any streaks, spots, or cracks
  • Easy to understand; well-explained; obvious
  • adverb
  • Completely; entirely; through the whole of
  • Away from; free from
  • verb
  • To recover from or remove a problem
  • To get rid of the entire contents of
  • To give permission for something to happen
  • To make a place or surface empty by removing
  • To prove that someone is not guilty or to blame

mathematical

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US / ˌmæθə'mætɪkl /

UK / ˌmæθəˈmætɪkəl /

A2
  • adjecitve
  • Concerning numbers and equations

see

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US / si: /

UK / si /

A1
  • verb
  • To go on a date with someone
  • To predict whether something is, or will be true
  • To understand what someone says
  • To use your eyes to look at something
  • To visit a place often for sightseeing or pleasure
  • To visit or meet with someone
  • To find out by waiting or looking
  • To watch (a game, movie or TV show)

six

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US / sɪks /

UK / sɪks /

A1
  • number
  • 6

could

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US / kəd /

UK / kʊd /

A1
  • other
  • Past form of 'can' to mean have ability
  • Used to ask for something politely, or to offer

meter

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US / ˈmi:tə(r) /

UK / ˈmitɚ /

A1
  • noun
  • Unit of length equal to 100 cm or about 39 inches
  • Device for measuring things e.g. gas
  • Device to put money into to rent a parking place
  • Rhythm of a poem
  • verb
  • To measure water, etc. when it has to be paid for

quickly

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US / ˈkwɪkli /

UK / ˈkwɪklɪ /

A1
  • adverb
  • Without taking a lot of time; fast

world

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US / wɜ:ld /

UK / wɜrld /

A1
  • noun
  • All the humans, events, activities on the earth
  • Political division due to some kind of similarity

before

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US / bɪˈfɔ:(r) /

UK / bɪˈfɔr,-ˈfor /

A1
  • adverb
  • At a time earlier than the present; previously
  • conjunction
  • In advance of something happening
  • preposition
  • In front of someone or something

know

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US / nəʊ /

UK / noʊ /

A1
  • verb
  • To be familiar with a person or place, thing
  • To feel sure or be convinced about something
  • To discover or be aware of something
  • To be able to distinguish
  • To have knowledge of things

everyday

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US / ˈevrideɪ /

UK / ˈɛvriˈde /

A1
  • adjecitve
  • Used or seen daily; for daily use; ordinary

have

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US / həv /

UK / hæv /

A1
  • verb
  • To drink, smoke, eat or use something
  • To experience the effects of something
  • To organize an event, or join in an activity
  • To own, possess, or hold something
  • To cause to happen or produce a particular effect

figure

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US / ˈfiɡə /

UK / ˈfɪɡjɚ /

A1
  • noun
  • Your body shape
  • Numbers in a calculation
  • Doll-like thing meant to represent a person
  • Picture or diagram giving information in a text
  • Person who is very important or famous
  • Shape of a person seen indistinctly or in outline
  • Amount that is expressed in numbers
  • verb
  • To appear in a game, play or event
  • To calculate how much something will cost
  • To understand after thinking; work out

encourage

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US / ɪn'kʌrɪdʒ /

UK / ɛnˈkɚrɪdʒ, -ˈkʌr- /

A2
  • verb
  • To increase the chance of something happening
  • To make someone more determined or confident

look

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US / lʊk /

UK / lʊk /

A1
  • noun
  • Person's beauty or physical attractiveness
  • Particular style of dress, clothes, or appearance
  • The way someone, something appears to be
  • Act of searching for or examining something
  • verb
  • To appear to be; seem

move

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US / mu:v /

UK / muv /

A1
  • noun
  • Act of moving a playing piece in chess, etc.
  • An action; doing something
  • Step taken to achieve a goal
  • verb
  • To cause someone to have certain emotions
  • To cause something to change to a different place
  • To change where people live or a business operates
  • To take action to do or achieve something

direction

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US / də'rekʃn /

UK / dɪˈrɛkʃən, daɪ- /

A2
  • noun
  • When someone tells people what to do
  • Describes the way you are going, e.g. North

kilogram

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US / ˈkɪləgræm /

UK / ˈkɪləɡræm /

A2
  • noun
  • 1000g

succeed

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US / sək'si:d /

UK / səkˈsid /

A2
  • verb
  • To have achieved what you were trying to achieve
  • To take over position of one who has died or left
  • To come after or replace in a series

movie

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US / ˈmu:vi /

UK / ˈmuvi /

A1
  • noun
  • Motion picture; film

bit

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US / bɪt /

UK / bɪt /

A1
  • noun
  • Device put in a horse's mouth to control it
  • Small piece of something
  • verb
  • (E.g. of fish) to take bait and be caught

its

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US / ɪts /

UK / ɪts /

A1
  • adjecitve
  • Referring to or belonging to ‘it’
  • determiner
  • Of something; belonging or related to something
  • other
  • Possessive form of “it”

all

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US / ɔ:l /

UK / ɔl /

A1
  • adverb
  • Completely; totally
  • determiner
  • Being every one of something
  • pronoun
  • 100% of something; the complete amount

their

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US / ðɛː /

UK / ðer /

A1
  • determiner
  • Belonging to them

both

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US / bəuθ /

UK / boθ /

A1
  • determiner
  • Used to refer to two things at the same time
  • pronoun
  • Used to refer to two things at the same time

they

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US / ðeɪ /

UK / ðe /

A1
  • pronoun
  • Two or more people, animals, or things

multiply

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US / ˈmʌltɪplaɪ /

UK / ˈmʌltəˌplaɪ /

B1
  • verb
  • To increase in number by reproducing/having babies
  • To increase something by a large quantity
  • To have increased by a large quantity
  • To calculate two numbers e.g. 2 x 4

very

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US / 'verɪ /

UK / ˈvɛri /

A1
  • adjecitve
  • Concerning a large degree or amount
  • adverb
  • A lot; much; many
  • Used to stress or emphasize a noun

travel

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US / ˈtrævl /

UK / ˈtrævəl /

A1
  • noun
  • Going to other places, esp. distant places
  • verb
  • To go to a place that is far away

reference

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US / 'refrəns /

UK / ˈrɛfərəns, ˈrɛfrəns /

A2
  • noun
  • A letter of recommendation, e.g. for a job
  • Note in a book, etc. giving source of information
  • A location on a map
  • verb
  • To cite a piece of research in speech or writing

question

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US / 'kwestʃən /

UK / ˈkwɛstʃən /

A1
  • noun
  • Issue or problems you are dealing with
  • What you ask about; issue
  • verb
  • To ask for or try to get information
  • To have or express concerns or uncertainty

fact

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US / fækt /

UK / fækt /

A1
  • noun
  • Something that is known or proved to be true

for

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US / fə(r) /

UK / fɔr,fə /

A1
  • preposition
  • Used to show the purpose, or need of something

vehicle

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US / ˈvi:əkl /

UK / ˈvi:hɪkl /

A2
  • noun
  • Machine (such as a car) used to carry things
  • Means of expressing, showing, or achieving

positive

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US / ˈpɒzətɪv /

UK / ˈpɑzɪtɪv /

A2
  • adjecitve
  • Showing agreement or support for something
  • Being sure about something; knowing the truth
  • Having the charge produced by electrons
  • Being good or useful
  • Showing that a chemical is present in a test

ask

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US / ɑ:sk /

UK / æsk /

A1
  • verb
  • To say to someone that you want something

difficult

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US / 'dɪfɪkəlt /

UK / ˈdɪfɪˌkʌlt, -kəlt /

A1
  • adjecitve
  • Hard; not easy; you need to work hard to do it

informal

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US / inˈfɔ:məl /

UK / ɪnˈfɔrməl /

B1
  • adjecitve
  • Casual; relaxed
  • Not official; not done by the rules

introduction

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US / ˌɪntrəˈdʌkʃn /

UK / ˌɪntrəˈdʌkʃən /

A2
  • noun
  • A first experience with something
  • Opening part of a text or piece of music
  • Explanation of something, e.g. a place
  • Announcement of a new product or service
  • Making someone known to another by name

talk

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US / tɔ:k /

UK / tɔk /

A1
  • noun
  • Style of speaking
  • Discussion between two countries
  • Giving information in front of people; lecture
  • Saying things or ideas to someone with words
  • verb
  • To make a formal speech about something
  • To say things or ideas to someone with words

mass

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US / mæs /

UK / mæs /

B1
  • noun
  • Religious ceremony in some Christian churches
  • Large amount or number of something
  • Main or largest part of something
  • Large number of people considered as a whole
  • Amount of matter that an object has
  • verb
  • To gather people or things into a large group

per

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US / pə(r) /

UK / pɚ /

A2
  • preposition
  • In the manner directed or suggested
  • For each; during each

start

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US / stɑ:t /

UK / stɑrt /

A1
  • noun
  • First time or place that a thing exists; beginning
  • First opportunity to achieve something, e.g. a job
  • Sudden action or movement because you are scared
  • other
  • Beginning of something in place or time
  • verb
  • To do, be or happen for the first time; begin
  • To turn something on

since

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US / sɪns /

UK / sɪns /

A1
  • adverb
  • At a point before the present time
  • conjunction
  • For this reason; because
  • preposition
  • From the time in the past that

through

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US / θru: /

UK / θru /

A2
  • adjecitve
  • having finished using or doing something
  • adverb
  • From the beginning of something until the end
  • preposition
  • Over, in, across an entire thing or place
  • Allowing you to pass between, or to
  • By a particular way or process; by the use of

few

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US / fju: /

UK / fju /

A1
  • pronoun
  • Not many, a small number

just

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US / dʒʌst /

UK / dʒʌst /

A1
  • adjecitve
  • Proper or appropriate; as is deserved
  • Doing or being what is right or fair
  • Legally correct; having enough evidence
  • adverb
  • Almost; nearly
  • Exactly at the time of
  • Exactly (the same as, like)

pause

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US / pɔ:z /

UK / pɔz /

A2
  • noun
  • A temporary break before continuing
  • Function on a device to stop and restart it
  • Sign to hold a musical note a bit longer
  • verb
  • To stop doing for a while before continuing

scalar

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US / ˈskeɪlə(r) /

UK / ˈskelɚ, -ˌlɑr /

C2
  • adjecitve
  • Variable quantity that cannot be resolved into components

define

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US / dɪ'faɪn /

UK / dɪˈfaɪn /

A2
  • verb
  • To explain the meaning of words
  • To set or mark the limits of something

well

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US / wel /

UK / wɛl /

A1
  • adjecitve
  • Being in a fortunate, good condition or state
  • Healthy and in good condition
  • adverb
  • In an acceptable, proper, or successful manner
  • In a complete, total, or full manner
  • A great and considerable degree
  • In a successful way, in a good or satisfactory way
  • exclamation
  • Used to begin or continue a particular statement
  • Used to show you want to start saying something
  • Used to express that you are waiting for a reply
  • You say this to change the topic of a conversation
  • Used to indicate you are making a final remark
  • noun
  • Long deep hole in the ground to get water
  • verb
  • To cause your eyes to fill with tears

time

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US / taɪm /

UK / taɪm /

A1
  • noun
  • Speed at which music is played; tempo
  • Point as shown on a clock, e.g. 3 p.m
  • Number of hours, minutes needed to do something
  • Occasion when something happens
  • Period or occasion that something occurred
  • Period in history or the past
  • Something measured in minutes, hours, days, etc.
  • How long an event takes; duration
  • verb
  • To check speed at which music is performed
  • To choose a specific moment to do something
  • To measure how long an event takes, e.g. a race
  • To schedule something to occur at a specific moment

set

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US / set /

UK / sɛt /

A1
  • adjecitve
  • Prepared for something; ready
  • noun
  • Complete group of something
  • Place where a television show or movie is filmed
  • Group of games in a tennis match
  • Device that receives radio or television signals
  • verb
  • To make a clock state or ring at a particular time
  • To decide upon or choose something
  • To make something ready for use (e.g. table)
  • To decide on a price for something
  • To become hard (of glue, concrete etc.)
  • To be located in a specific place or time
  • To put (e.g. a vase) down carefully in a place
  • To put someone in a certain condition or state
  • (Of the sun) to go lower than the horizon

velocity

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US / və'lɒsətɪ /

UK / vəˈlɑsɪti /

B1
  • noun
  • Speed in a given direction

depend

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US / dɪˈpend /

UK / dɪˈpend /

B1
  • verb
  • Be controlled or determined by (someone/something)

much

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US / mʌtʃ /

UK / mʌtʃ /

A1
  • adjecitve
  • Very; to a high level or degree
  • adverb
  • A lot; large amount; a high degree of
  • Nearly; basically
  • On many occasions; often
  • noun
  • A large amount; a great quantity

those

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US / ðəʊz /

UK / ðoz /

A1
  • determiner
  • The people or things we are talking about
  • pronoun
  • The objects far from the speaker

keep

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US / ki:p /

UK / kip /

A1
  • noun
  • Large, strong tower in the middle of a castle
  • Money spent on you so you can live in a place
  • verb
  • To continue doing something; not to stop
  • To stop balls going in a goal in sports
  • To not give back or return something
  • (Of food) to not spoil or not rot
  • To take possession of something to own, e.g. a pet
  • To have and continue to hold something
  • To do something that you have promised or agreed
  • To stay in a certain place or condition
  • To maintain the rules

momentums

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US / məʊˈmɛntəmz /

UK / moʊˈmɛntəmz /

A1
  • other

where

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US / hwɛə /

UK / hwɛr, wɛr /

A1
  • conjunction
  • At or in the place which
  • In whatever place
  • pronoun
  • Word you use to ask the location of something

something

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US / ˈsʌmθɪŋ /

UK / ˈsʌmθɪŋ /

A1
  • adverb
  • In some degree or measure
  • noun
  • a person or thing of some value or consequence
  • pronoun
  • Thing that is not yet known or named
  • Approximately

lot

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US / lɒt /

UK / lɑt /

A1
  • noun
  • What happens to a person in life from chance; fate
  • A group of people seen together
  • Item for sale at an auction
  • Small area of land used for a purpose e.g. parking

from

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US / frəm /

UK / frʌm, frɑm,frəm /

A1
  • preposition
  • Starting at a particular place, time or level

two

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US / tu: /

UK / tu /

A1
  • number
  • 2

along

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US / əˈlɒŋ /

UK / əˈlɔ:ŋ /

A1
  • adverb
  • As a companion; taken with someone
  • preposition
  • At a point on a line

squeeze

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US / skwi:z /

UK / skwiz /

C1
  • noun
  • Amount of liquid from firmly pressing e.g. orange
  • Act of putting pressure on, as to get liquid out
  • When there is not enough space for things/people
  • Act of firmly pressing on two or more sides
  • verb
  • To force or threaten someone to give you something
  • To strongly compress something to get liquid out
  • To be pressed together or crowded into an area
  • To press together the opposite sides of something
  • To reduce the amount of something

think

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US / θɪŋk /

UK / θɪŋk /

A1
  • verb
  • To have an idea about something without certainty
  • To have an idea, opinion or belief about something

picture

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US / 'pɪktʃə(r) /

UK / ˈpɪktʃɚ /

A1
  • noun
  • General situation or state of being
  • Mental image of what something is or looks like
  • Movie; film
  • Painting, drawing or photograph on paper or screen
  • verb
  • To understand or imagine something
  • To imagine someone or something in an image

over

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US / 'əʊvə(r) /

UK / ˈovɚ /

A1
  • adverb
  • Finished; no longer happening
  • Towards the ground/away from a standing position
  • noun
  • A set of six consecutive balls bowled in cricket
  • other
  • Finished
  • preposition
  • Showing the relation when a thing is above another
  • On or covering something
  • Above or across something
  • More than you need
  • From one side to the other
  • In the direction of; toward

frame

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US / freɪm /

UK / frem /

A2
  • noun
  • Structure that holds a picture or photo
  • A person's body shape determined by their skeleton
  • Main part of structures supporting the other parts
  • verb
  • To make a person that is not guilty appear guilty
  • To put say or write something in a careful way
  • To put a picture in a protective structure

out

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US / aʊt /

UK / aʊt /

A1
  • adverb
  • No longer stylish (e.g. fashion)
  • Away from home, business, or the usual place
  • In a direction/movement away from inside or center
  • noun
  • Act when a batter cannot continue playing
  • verb
  • To tell people a secret

and

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US / ənd /

UK / ənd, ən,ænd /

A1
  • conjunction
  • Used to refer to two or more things
  • Plus; in addition; on top of that
  • Used to introduce an action that follows another

leave

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US / li:v /

UK / liv /

A1
  • noun
  • Permission to do something
  • Vacation time; time off work
  • verb
  • To go away from; depart
  • To gift property to someone after you die
  • To allow something to continue happening
  • To let something remain unused or available
  • To let something or someone remain somewhere

anything

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US / ˈeniθɪŋ /

UK / ˈɛniˌθɪŋ /

A1
  • pronoun
  • A thing of any kind

large

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US / lɑ:dʒ /

UK / lɑ:rdʒ /

A1
  • adjecitve
  • Big; of great size; broad, tall, wide, or fat

come

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US / kʌm /

UK / kʌm /

A1
  • verb
  • To arrive at a place
  • (Of mail) to be delivered
  • To move toward someone; go with someone
  • To reach a certain point or state

version

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US / ˈvə:ʃən /

UK / ˈvɚʒən, -ʃən /

A2
  • noun
  • Different way that someone interprets something
  • New or different form of something
  • An updated form of some software

assign

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US / ə'saɪn /

UK / əˈsaɪn /

B2
  • verb
  • To give someone a particular job to do
  • To give someone credit or blame for something
  • Subtitles section
  • In this video, we're going to talk a little bit about momentum.
  • And I encourage you to think about what does momentum mean in everyday language?
  • If I were to tell you that a business has a lot of momentum, many people would imagine that means that it's doing really well.
  • It's hard to stop that business from succeeding.
  • If I were to tell you that, and let's say a movie star has a lot of momentum, it means that they keep making really, really, really good movies.
  • It's hard to stop them.
  • And in physics, momentum essentially has that same notion.
  • In fact, these everyday language versions of momentum really came from the physics version of it.
  • And an informal definition, you could think of it as how hard to stop something.
  • Stop something.
  • So with that very informal definition, we'll get a little bit more mathy in a few seconds.
  • I have two pictures here, and let's say both of these vehicles, so we have a big 18-wheeler truck here, and here we have a Formula One car.
  • Let's say that they both have a velocity of 20 meters per second, positive 20 meters per second.
  • We'll just think in one dimension.
  • So let's say it's going to the right at 20 meters per second.
  • So that's a magnitude and a direction.
  • We've got a positive here to make it clear that I'm giving a direction here.
  • So they're both going in the positive direction at 20 meters per second.
  • But you can imagine their masses are very different.
  • This large truck would have a mass of, let's just say, 30,000 kilograms.
  • That's roughly actually what an 18-wheeler truck's mass is.
  • I looked it up before this video.
  • And let's say the mass of this Formula One car is about 1,000 kilograms.
  • Now pause this video and think about which one do you think would have more momentum?
  • All right, well, you're probably imagining trying to stop either of these.
  • And I guess either of these would be difficult to stop, but a truck going at 20 meters per second seems a lot harder than the Formula One car.
  • This thing seems like it would just be able to drive through anything.
  • So if you picked the truck having a higher momentum when it's going at the same velocity as a Formula One car, you'd be right.
  • But an interesting question is, well, how can I quantify that?
  • And that's where we have the mathematical definition of momentum.
  • And momentum is defined as mass times velocity.
  • And because velocity is a vector, it's not just a magnitude, we assign a direction.
  • So we set it in the positive direction.
  • If we're in one dimension, if we set it in the negative direction, we'd be going to the left.
  • That's maybe the convention we could use.
  • And since it's a scalar, which is mass, times a vector, momentum is also going to be a vector.
  • You're going to have a momentum in a certain direction.
  • So pause this video and see if you can calculate the momentum for each of these vehicles.
  • And see also if you can figure out what the units are going to be.
  • All right, now let's think about the momentum for this 18-wheeler.
  • It is going to be its mass, which is 30,000 kilograms, times its velocity, which is positive 20 meters per second.
  • And so when I multiply those two things, I am going to get, let's see, I'm gonna get a six with one, two, three, four, five zeros.
  • One, two, three, four, five, zero, 600,000.
  • And then the units are kilogram times meter per second.
  • Kilogram meter per second.
  • That's the momentum of the truck.
  • Now, what about the Formula One car?
  • Pause the video and try to calculate that momentum.
  • All right, well, same notion.
  • I'll have to squeeze it in right over here.
  • The momentum here is the mass, 1,000 kilograms.
  • 1,000 kilograms times the velocity, positive 20 meters per second.
  • I'm stressing the positive because we're in one dimension and I'm saying positive is one direction, negative is the other direction.
  • So I am giving a direction here.
  • And so this momentum is going to be equal to 20,000 kilogram meters per second.
  • Kilogram meters per second.
  • And so when you evaluate the momentums, it's clear mathematically that the truck has much more momentum than this Formula One car.
  • It has 30 times the momentum.
  • Now, I know what some of y'all are thinking.
  • Well, this is just from the reference frame.
  • If I'm standing still on the ground while this truck and car are moving by, but what if I were moving along with them?
  • Would they have the same momentum?
  • And if you were asking that question, it's a very good one.
  • And the answer is no, the momentum depends on the frame of reference.
  • So let's say that you are able to travel very quickly in, well, let's say you're in a car here, and you're also going at 20, positive 20 meters per second.
  • So you're going in the same direction as the truck.
  • Well, relative to you, the truck's velocity is now zero.
  • So from your frame of reference, if you wanted to calculate momentum, you would have the mass of the truck, 30,000 kilograms, but from your frame of reference, the velocity would now be zero.
  • So if you're traveling in this car at the same velocity as that truck, the momentum you would calculate is zero.
  • Now, what would then have momentum?
  • Well, in that world, let's say that there's a big rock over here that, let's say this thing, 100,000 kilograms.
  • Well, when you were standing on the ground, that thing would have no momentum.
  • But now that you're moving 20 meters per second to the right, positive 20 meters per second, the rock in your frame of reference would look like it's going at negative 20 meters per second.
  • It would look like it's going 20 meters per second to the left.
  • And so this would now, if you're moving in the same frame of reference as that truck, this rock would then look like it has a very negative momentum.
  • And I encourage you to calculate it if you like.
  • But I'll leave you there.
  • This is really just an introduction to momentum.
  • But once you get an intuition for it, all sorts of interesting things in physics start to emerge from it.