 AQA GCSE - Forces B

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Stopping distances, Free Body Diagrams, Momentum, Moments, Stretching.

(No work done or Energy in this test - see Energy unit)

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. Which of these speeds might be typical for a bicycle?

• A). 0.6 m/s
• B). 6 m/s
• C). 60 m/s
• D). 600 m/s

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

11. As the car accelerates, a strong wind also pushes on the car as shown in this diagram showing the view from above the car. . Which of the following arrows shows the NET force (resultant force) acting on the car from these 2 forces? 12. To increase the momentum of a toy car, which two quantities must be increased?

 1st Quantity 2nd quantity A. mass velocity B. weight acceleration C. acceleration mass D. mass force