P5 Rest

Question 1

NEWTON’S THIRD LAW – THE LAW OF INTERACTION

Answer 1

Whenever two objects interact, they exert equal and opposite forces on each other.

Question 2

Newton second law means

Answer 2

• Forces always come in pairs.
• The forces are equal in size.
• The forces act in opposite directions.
• The forces act on different objects.

Question 3

Newton’s Third Law in Simple Terms:

Answer 3

If object A pushes on object B,
then object B pushes back on object A
with the same size force,
but in the opposite direction

Question 4

Examples You Must Memorise:

Answer 4

Standing on the floor:
• You push down on the floor (your weight).
• The floor pushes up on you with an equal and opposite normal contact force.

Question 5

A rocket launches: example

Answer 5

• The rocket pushes hot gas downwards.
• The gases push the rocket upwards with an equal and opposite force.

Question 6

Punching a wall: example

Answer 6

• Your hand exerts a force on the wall.
• The wall pushes back on your hand with an equal and opposite force (ouch!).

Question 7

A car drives forward:

Answer 7

• The wheels push backwards on the road.
• The road pushes forwards on the wheels.

Question 8

Describe the pair of forces when a person jumps off a boat.

Answer 8

A: The person pushes backwards on the boat, and the boat pushes the person forwards with an equal and opposite force.

Question 9

A bat hits a ball. Describe the forces involved.

Answer 9

The bat exerts a force on the ball.
The ball exerts an equal and opposite force on the bat.

Question 10

What does Newton’s Third Law state?

Answer 10

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

Question 11

Do Newton’s Third Law pairs act on the same object

Answer 11

❌ No — they act on different objects.

Question 12

A horse pulls a cart. What is the Newton’s Third Law pair

Answer 12

The cart pulls back on the horse with an equal and opposite force.

Question 13

Why doesn’t a book fall through a table?

Answer 13

The book pushes down on the table; the table pushes up with an equal and opposite force.

Question 14

: What happens when you walk?

Answer 14

You push back on the ground, the ground pushes you forward with an equal and opposite force.

Question 15

What is stopping distance equation

Answer 15

Stopping Distance = Thinking Distance + Braking Distance

Question 16

Thinking Distance

Answer 16

The distance a car travels while the driver is reacting.
• Time it takes from seeing a hazard to pressing the brakes.

Question 17

Braking Distance

Answer 17

The distance the car travels after the brakes are applied until it stops.

Question 18

Stopping Distance

Answer 18

The total distance the car travels from seeing the hazard to fully stopping.

Question 19

What Increases Thinking Distance? List

Answer 19

Tiredness
Alcohol drugs
Distractions
Speed

Question 20

Factor Tiredness

Why it increases thinking distance

Answer 20

Slower reaction time

Question 21

Alcohol drugs Why it increases thinking distance

Answer 21

Affects brain and reflexes

Question 22

Distractions
Why it increases thinking distance

Answer 22

Less attention to the road

Question 23

Why it increases thinking distance
Speed

Answer 23

Faster speed = more distance covered before reacting

Question 24

What Increases Braking Distance? List

Answer 24

Icy road
Poor brakes
Worn tyres

Question 25

Why it increases braking distance Icy roads

Answer 25

Less grip = more skidding

Question 26

Why it increases braking distance Worn tyres

Answer 26

Less friction with road

Question 27

What type of energy is Braking Distance: affected by

Answer 27

Braking distance is affected by kinetic energy.

Question 28

Energy Link for Braking Distance:

Answer 28

• The faster the vehicle, the more kinetic energy it has. • The brakes need to do more work to stop the car:

Question 29

Explain two factors that increase the stopping distance of a vehicle. (4 marks)

Answer 29

✅ 1. Increased speed – this increases both thinking and braking distance because the car covers more ground in the same time. ✅ 2. Wet roads – less friction between the tyres and the road, so braking distance increases

Question 30

What is thinking distance?

Answer 30

The distance travelled while reacting to a hazard.

Question 31

What is braking distance?

Answer 31

The distance travelled after pressing the brakes until the car stops.

Question 32

A driver is tired and driving fast. What happens to their stopping distance?

Answer 32

It increases – tiredness affects thinking distance, speed affects both.

Question 33

Why does a wet road increase braking distance?

Answer 33

Less friction between tyres and the road.

Question 34

What is Braking Distance?

Answer 34

Braking Distance = the distance a vehicle travels after the brakes are applied until it comes to a complete stop.

Question 35

What Happens During Braking? Step by step

Answer 35

1. Brake pads press against wheels. 2. Friction between pads and wheels causes the car to slow down. 3. The kinetic energy of the moving car is transferred to thermal energy in the brakes. 4. The car decelerates (slows down) until it stops. The more kinetic energy the car has, the more work the brakes must do.

Question 36

What Factors Affect Braking Distance?

Answer 36

Speed Condition of brakes Condition of tyres Downhill slopes

Question 37

Speed Why it affects braking distance

Answer 37

Higher speed = more kinetic energy = longer to stop

Question 38

Condition of brakes Why it affects braking distance

Answer 38

Worn brakes have less friction = longer to stop

Question 39

Condition of tyres Why it affects braking distance

Answer 39

Worn tyres reduce friction with the road

Question 40

Downhill slopes Why it affects braking distance

Answer 40

Gravity adds force, increasing distance

Question 41

Physics Behind It: braking distance

Answer 41

The braking force times the distance = energy transferred from movement (kinetic energy) to heat.

Question 42

A car is driving on a wet road. Explain why the braking distance is longer than on a dry road

Answer 42

A: On a wet road, there is less friction between the tyres and the road surface. This means the car needs to travel further before stopping after the brakes are applied, so the braking distance increases.

Question 43

What is braking distance?

Answer 43

The distance a car travels after braking until it fully stops.

Question 44

Name three factors that increase braking distance.

Answer 44

High speed, icy road, worn brakes

Question 45

Does reaction time affect braking distance?

Answer 45

❌ No — it affects thinking distance, not braking