Edexcel GCSE - Forces B

Page 1

Stopping distances, Circular Motion, Momentum, Free Body Diagrams

Topics 2 and 9 (paper 1 and 2)

These questions are about a lorry stopping when a dog jumps out into the road.

The table below shows the speed of the lorry at a time after the dog has jumped out.

 Velocity (m/s) time (s) 20 0 20 0.2 20 0.4 16 0.8 12 1.2 8 1.6 4 2.0 0 2.4

1. What was the driver's 'thinking' time?

2. How far did the lorry travel in this time?

3. What was the driver's braking time?

4. Calculate the lorry's deceleration in m/s2.

5. What 2 factors could have affected the driver's thinking time?

• A). Poor brakes and tiredness
• B). Alcohol and the weight of the lorry
• C). Medical drugs and lack of sleep
• D). The quality of the tires and the road conditions

6. What 2 factors could affect the driver's braking time?

• A). Poor brakes and tiredness
• B). Alcohol and the weight of the lorry
• C). Medical drugs and lack of sleep
• D). The quality of the tires and the road conditions

7. What is the name of the force that causes circular motion, and in which direction does it act?

• A). Centripetal force, acting forwards.
• B). Centripetal force, acting towards the centre of the circle.
• C). Centrifugal force, acting forwards.
• D). Centrifugall force, acting towards the centre of the circle.

8. As the Earth orbits the Sun, which measurement is constantly changing?

• A). The size of the force causing circular motion
• B). The velocity of the Earth
• C). The speed of the Earth
• D). The distance between the Earth and the Sun

9. A remote controlled car is switched on and accelerates from rest. Which of these 4 free body diagrams correctly shows the relative sizes of the forces acting on the car?

10. The car in question 9 is hard to accelerate if the mass is larger. This is called the car's

• A). inertial mass
• B). gravitational mass
• C). atomic mass
• D). molar mass