Forces And Motion

Question 1

What is velocity?

Answer 1

The speed in a given direction.

Question 2

Is displacement a scalar or vector quantity?

Answer 2

Vector quantity.

Question 3

What is acceleration?

Answer 3

The rate of change in velocity.

Question 4

An object moving at a constant speed but _________________________ is also accelerating.

Answer 4

changing direction continually

Question 5

Velocity changes if either the __________________ or the _______________ changes.

Answer 5

magnitude
direction

Question 6

What is uniform motion?

Answer 6

When an object is moving in a straight line at a constant speed.

Question 7

What is non uniform motion?

Answer 7

When an object’s speed or direction changes when moving.

Question 8

In uniform motion, the resultant force is __.

In non uniform motion, the resultant force is _______.

Answer 8

0
not 0

Question 9

In Newton’s second law,

The acceleration of an object _____________ if the resultant force on it ______________,

And _____________ if the mass of the object ______________.

Answer 9

increases
increases

decreases
increases

Question 10

What is inertial mass?

Answer 10

The measure of how difficult it is to change the velocity of an object.

Question 11

What does the symbol ~ mean?

Answer 11

That a value is approximate.

Question 12

In the force on acceleration of an object practical using a vacuum cleaner to blow out air,
a constant stream of air ______________________ between the glider and the air track.

Answer 12

reduces the friction

Question 13

Acceleration is _______________________ to the force exerted on the object.

Answer 13

directly proportional

Question 14

In the investigating acceleration of an object practical:

1. Attach a toy car to a piece of string _______________________.
2. Attach the other end of the string to a 100g _______.
3. Draw ________________ of _________________.
4. Hold the toy car at the starting point, then let go and record the time the car ______________________ with a ___________________.
5. ____________ the experiment several times but ____________ the mass on the end of the string and ________________________________.
6. Plot results on a __________.

Answer 14

looped around a pulley

mass

chalk lines
equal intervals

passes each chalk interval
mobile phone

Repeat
decrease
transfer the mass onto the toy car

graph

Question 15

Because there is a resultant force acting through the string, what happens to the toy car attached?

Answer 15

The toy car will accelerate along the desk.

Question 16

In the acceleration practical, the object affected is not only the toy car, but also the string and mass attached.
Why?

Answer 16

Because they are all attached to each other.

Question 17

As you increase the mass of the toy car, acceleration ________________.

Answer 17

decreases

Question 18

Explain how protective pads help to reduce injury when the players collide. (3)

Protective pads increase the _____________ to stop,
so the change of _______________ decreases.

___________________ on the ice hockey players.

Answer 18

time taken
momentum

Reducing the force

Question 19

What is inertia?

Answer 19

The tendency of an object to continue in its state of rest or motion

Question 20

Explain why the egg is less likely to break when dropped onto soft foam rather than onto a
concrete floor? (3)

Soft foam _____________ the time taken to stop,

decreasing the change in ________________

___________________ on the egg.

Answer 20

increases
momentum
reducing the force

Question 21

Explain why atmospheric pressure decreases with increasing altitude. (3)

Air molecules _____________________ create pressure.

So the ________________________ with a surface decreases.

Answer 21

colliding with a surface
number of collisions

Question 22

The further a swimmer dives below the surface of the sea, the greater the pressure on the
swimmer.
Explain why: (2)

Increasing _________ increases the _____________ of the water above the swimmer.
increasing the __________________ acting on the swimmer.

Answer 22

depth
volume

weight of water

Question 23

What is the difference between distance and displacement?
(1)

Answer 23

Distance is a scalar and displacement is a vector.

Question 24

What property of springs would make the mattress soft? (2 marks).

Answer 24

Springs having a low spring constant because they can compress by a larger amount.

Question 25

Explain how forces need to change so an aeroplane can land? (4 marks).

Thrust must ___________.
So there is a ________________ in the opposite direction.
The lift must ____________ (because the weight stays the same).
So there is a ___________________________.

Answer 25

decrease
resultant force
decrease
resultant downwards force