2024年5月13日发(作者：小米手环怎么恢复出厂设置)

IGCSE Physics 英文物理词汇知识点整理

1.

Acceleration: Is the rate of change in velocity per unit of time

2.

Acceleration= Final Speed + Initial Speed ÷ Time Taken:

Formula to find acceleration

3.

Acceleration is not constant: If speed/time graph is curved

then it means

4.

Air resistance: Objects in the air are slowed down by

5.

atm: Represents ~760 mm of mercury

6.

Barometer: An instrument measuring atmospheric pressure,

used especially in forecasting the weather and determining

altitude

7.

Centre of mass: imaginary point in a body where total mass of

body seems to be acting

8.

Centripetal force: is the force acting towards the center of a

circle.

It is a force that is needed, not caused, by circular motion

9.

Circular Motion: the name of the motion in which an object at

steady speed in circular orbit is always accelerating as its

direction is changing, but it gets no closer to the center

10.

Clocks: Interval of time is measured using

11.

Conservation of energy: energy cannot be created or

destroyed, when work is done, energy is changed from one

form to another, What is this called ?

12.

Deceleration or negative acceleration: Means the velocity of

a body is decreasing

13.

Density: Describes how compact or concentrated something is

14.

Density= Mass ÷ Volume: Formula for Density

15.

Distance= Final Speed + Initial Speed ÷ 2 x Time: Formula of

distance with constant acceleration

16.

Distance= Speed x Time: Formula of distance with constant

speed

17.

Efficiency= input ÷ output x 100%: Formula of Efficiency

18.

Efficiency description: Tells how much of the energy

transferred is useful.

19.

Energy: Amount of work and its measured in Joules (J)

20.

First law of motion: This law states that "If no external for is

acting on it, an object will, if stationary, remain stationary, and

if moving, keep moving at a steady speed in the same straight

line"

21.

Force: Describes a physical energy that can be seen or felt, it

may produce a change in size and shape of a body by given

an acceleration or deceleration or by change in direction.

22.

Force= Mass x Acceleration: Formula of force

23.

Formula of Kinetic energy:

24.

Formula to find Gradient:

25.

Friction: The force between two surfaces which impedes

motion and results in heating

26.

ft=mv-mu: Formula of Impulse

27.

G.P.E= mgh: Formula of gravitational potential energy

28.

Gravity: The downwards acceleration of an object is caused by

29.

Gravity=10m/s: Acceleration of free fall for a body near to the

Earth is

30.

Height difference: In manometer, this different shows the

excess pressure in addition to the atmospheric pressure

31.

Impulse: product of force and time for which it acts

32.

Joules: The unit for work and energy

33.

Levers: are force magnifiers

34.

Linear momentum: Is product of mass and velocity

35.

Manometer: Measures the pressure difference

36.

Mark three points on the edge of the card,

Make a hole using a pin on each point,

Hang it on a cork board and make a line

when it is stable,

Do this for all three points,

Where all three lines intersect, this is the

center of mass: How to workout the center of mass

37.

Mass: Amount of matter an object contains, and is a property

that 'resists' change in motion

38.

Meter(m): SI unit for length

39.

Micrometer Screw Gauge: Used to measure very small

distances

40.

Moment(Nm)= Force(N) x Distance from pivot(m): Formula

for Moment

41.

Non-renewable sources: These sources of energy will run out

eventually.

42.

p=mv: Formula for Linear momentum

43.

Pascal(pa)= n/m^2: Unit of pressure

44.

Positive acceleration: Means the velocity of a body is

increasing

45.

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48.

Power: Is the rate of work

Power(w)= work done ÷ time taken: Formula to workout power

Pressure: Is defined as the normal force per unit area of a surface

Pressure(pa)= density(kg/m^3) x gravity(m/s^2) x height(m)

So, p= hpg: Formula of pressure in liquids

49.

50.

Pressure(Pa)= force(n) ÷ area(m^2): Formula of pressure in solids

Principle of conservation of Linear momentum: When bodies in a system interact, total momentum remains constant provided no

external force acts on the system

Renewable sources: These sources will never run out.

Ruler: used to measure length for distances between

1mm and 1meter

Scalar Quantity: is a quantity that only has a magnitude (so it can only be positive) for example speed.

Second(s): SI unit for time

Speed: the distance an object moves in a time frame

Speed= Distance ÷ Time: Formula for speed

Third law of motion: This law states that if object A exerts a force on object B, then object B will exert an equal but opposite force on

object A

Vector Quantity: This quantity has a direction as well as a magnitude, for example velocity, which can be negative

Watts: Unit of power

Weight: Is the force of gravity acting on an object, measured in Newtons

Weight= Mass x Gravity: Formula of Weight

Work: Is done whenever a force makes something move

Work done(J)= force(n) x distance: Formula for work done

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