P5 Homework - Retrieval Practice

Question 1

What is a contact force? Give an example.

Answer 1

A force that must touch to have an effect
e.g. Friction
Air resistance

Question 2

What is a non-contact force? Give an example

Answer 2

A force that does not have to touch to have an effect
e.g. Gravity
Magnetic Force
Electrostatic Force

Question 3

What is mass measured in?

Answer 3

Kilograms (kg)

Question 4

What is weight measured in?

Answer 4

Newtons (N)

Question 5

What is the equation for working out weight?

Answer 5

Weight (N) = Mass (kg) x Gravity (N/kg)

Question 6

What affect do unbalanced forces have on movement?

Answer 6

Unbalanced forces (there is a resultant force) cause a CHANGE IN MOVEMENT e.g. speeding up or slowing down

Question 7

What affect do balanced forces have on movement?

Answer 7

Balanced forces (NO resultant force) cause NO CHANGE IN MOVEMENT
e.g. stationary or steady speed

Question 8

What is acceleration measured in?

Answer 8

m/s2

Metres per second squared

Question 9

What 2 things increase the total stopping distance?

Answer 9

Thinking distance (distance travelled in the time it takes to push the brake)
Braking distance (distance travelled in the time it takes the vehicle to stop)

Question 10

What is thinking distance?

Answer 10

The distance travelled in the time it takes to react and push the brake (reaction time)

Question 11

What is stopping distance?

Answer 11

The distance travelled in the time it takes the vehicle to stop

Question 12

What can affect thinking distance?

Answer 12

Speed
Tiredness
Drugs/Alcohol
Distractions

Question 13

What can affect braking distance?

Answer 13

Speed
Road surface (less grip will increase braking distance)
Weather (rain/ice will reduce grip)
Condition of tyres (bald tyres will increase braking distance)
Condition of brakes

Question 14

What do these parts of a DISTANCE-time graph represent?

a) A flat line
b) Straight line upwards
c) Straight line downwards

Answer 14

a) Flat = stopped
b) Straight line upwards = Steady speed
c) Straight line downwards = Steady speed back to start

Question 15

What do these parts of a VELOCITY-time graph represent?

a) A flat line
b) Straight line upwards
c) Straight line downwards

Answer 15

a) Flat = Steady speed
b) Straight line upwards = Constant Acceleration
c) Straight line downwards = Constant deceleration

Question 16

How can you investigate how force affects the extension of a spring (Hookes law)?

Answer 16

1) Use a stand and clamp to suspend a spring
2) Attach the spring
3) Add 10g mass and measure the EXTENSION (how much longer it gets)
4) Repeat with 20g, 30g, 40g, 50g

Question 17

In the air track practical, how can you change the mass?

Answer 17

Add masses to the trolley

Question 18

In the air track practical, how can you change the Force?

Answer 18

Add masses to the hook pulling the trolley

remember to add these to the trolley to keep the mass of the system the same

Question 19

What is an air track?

How does this improve our equipment to investigate acceleration?

Answer 19

An air track is a track that releases a layer of air (like air hockey)
This REDUCES FRICTION

Question 20

Which equation is the air track experiment designed to investigate?

Answer 20

Force (N) = Mass (kg) x Acceleration (m/s2)

Question 21

How do you measure the extension of a spring?

Answer 21

Record the length of the spring before it is stretched and remove this from the final length.
This will tell you how much LONGER the spring is.