# Topic 5+6-Forces and Waves Flashcards Preview

## Physics Gcse AQA 9-1 > Topic 5+6-Forces and Waves > Flashcards

Flashcards in Topic 5+6-Forces and Waves Deck (70)
1
Q

What are the two types of quantities?

A
• Scalar.

- Vector.

2
Q

What quantity is force?

A

Vector.

3
Q

What quantity is speed?

A

Scalar.

4
Q

What is a scalar quantity?

A

Something that only has a magnitude but no direction.

5
Q

What is a vector quantity?

A

Something that has a magnitude and a direction.

6
Q

All forces are…

A

Contact or non-contact.

7
Q

What is an interaction pair?

A

A pair of forces that are equal and opposite and act on two interacting objects.

8
Q

What is the equation for weight?

A

mass x gravitational field strength.

9
Q

Are mass and weight directly or indirectly proportional?

A

Directly proportional.

10
Q

What do free body diagrams show?

A

All the forces acting on an object.

11
Q

What is meant by the resultant force?

A

The overall force on a point or object.

12
Q

What is the equation for work done?

A

Force x distance.

13
Q

When is an object in equilibrium?

A

When all of the forces add together to equal zero.

14
Q

What are objects that have been elastically deformed called?

A

Elastic objects.

15
Q

What does it mean if an object has been elastically deformed?

A

It can go back to its original shape and length after a force has been removed.

16
Q

What is the equation for force?

A

Spring constant x extension.

17
Q

What is the equation for a moment of a force?

A

Force x distance.

18
Q

What is the equation for pressure?

A

Force over area of surface.

19
Q

What is meant by density?

A

How close the particles are together in a substance.

20
Q

If the upthrust is equal to an objects weight…

A

The object will float.

21
Q

What is atmospheric pressure caused by?

A

Air molecules colliding with the surface of the earth.

22
Q

As the altitude increases what happens to the atmospheric pressure?

A

It decreases.

23
Q

Why does the atmospheric pressure decrease with higher altitude?

A

Because less particles are able to collide with the surface of he earth.

24
Q

What is the typical speed of a person walking? (idk why we need to know this but it says we do)

A

1.5 m/s

25
Q

What is the typical speed of a car?

A

25 m/s

26
Q

What is acceleration?

A

The change in speed over time.

27
Q

What direction does friction always act?

A

In the opposite direction to movement.

28
Q

What is drag?

A

The resistance you get in a fluid.

29
Q

what counts as a fluid?

A

Liquid or gas.

30
Q

What does newtons first law say?

A

That a resultant force is needed to make something start moving, speed up or slow down.

31
Q

What is the equation for resultant force?

A

Acceleration x mass.

32
Q

What does inertia mean?

A

The tendency for motion to remain unchanged.

33
Q

What does newtons third law say?

A

When two objects interact, the forces they exert on each other are equal and opposite.

34
Q

What is your thinking distance affected by?

A

35
Q

What is meant by your thinking distance?

A

How far the car travels due to your reaction time.

36
Q

What is meant by breaking distance?

A

How far the car travels under a breaking force.

37
Q

What affects the breaking distance?

A
• Speed.
• Weather.
38
Q

What does braking rely on?

A

Friction between the brakes and the wheels.

39
Q

What test can you use to test reaction times?

A

The ruler dropping test.

40
Q

A
• Drugs.

- Tiredness.

41
Q

What is the equation for momentum?

A

Mass x velocity.

42
Q

What quantity is momentum?

A

Vector.

43
Q

What is the idea that in a closed system the total momentum before an event is the same as after called?

A

The conservation of momentum.

44
Q

What is the conservation of momentum?

A

The idea that in a closed system the total momentum before an event is the same as after the event.

45
Q

What is meant by a closed system?

A

No forces are acting on it.

46
Q

What causes momentum to change?

A

Force.

47
Q

What direction do waves transfer their energy?

A

In the direction they are travelling.

48
Q

What is meant by the amplitude of a wave?

A

The maximum displacement of a point on the wave from its undisturbed position.

49
Q

What are the two types of waves?

A
• Transverse.

- Longitudinal.

50
Q

What are the oscillations like in transverse waves?

A

Perpendicular to the direction of energy transfer.

51
Q

What does oscillation mean?

A

Vibration.

52
Q

what are the oscillations like in longitudinal waves?

A

Parallel to the direction of energy transfer.

53
Q

What is the equation for wave speed?

A

Frequency x wavelength.

54
Q

What can you use the measure the speed of sound?

A

An oscilloscope.

55
Q

What is the speed of sound?

A

330m/s.

56
Q

What happens when waves arrive at a boundary between two materials?

A

They can be absorbed, transmitted or reflected.

57
Q

What does it mean when waves are transmitted?

A

They pass straight through.

58
Q

What is the rule for when waves are reflected?

A

Angle of incidence = angle of reflection.

59
Q

What is meant by the angle of incidence?

A

The angle between the incoming wave and the normal.

60
Q

What is meant by the angle of reflection?

A

The angle between the reflected wave and the normal.

61
Q

What can reflection be?

A

Specular or diffused.

62
Q

When does specular reflection happen?

A

When a wave is reflected in a single direction by a smooth surface.

63
Q

When does diffuse reflection happen?

A

When a wave is reflected by a rough surface.

64
Q

Why does diffuse reflection happen?

A

The normal is different for each incoming ray.

65
Q

What is meant by the normal?

A

The imaginary line that is perpendicular to the surface at the point of incidence.

66
Q

A

Oscillating charges.

67
Q

What are EM waves made up of?

A

Oscillating charges.

68
Q

The frequency of waves produced will be equal to…

A

The frequency of the alternating current.

69
Q

What are radio waves mainly used for?

A

Communication.

70
Q

What is meant by a perfect black body?

A