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.

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

2. What was the driver's braking time?

4. 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

5. A tractor pulls a plough 2000m across a field using a force of 8000N.

What is the work done?

6. If the same tractor produces the same force and does 2MJ of work, how far did it go?

7. A 2kg brick is thrown at 3 m/s. It has a kinetic energy of

• A. 6J
• B. 9J
• C. 3J
• D. 18J

8. A 0.1kg lump of sticky blue tac is thrown at a velocity of 8 m/s. It has a momentum of

• A) 0.08 kg m/s
• B) 0.8 kg m/s
• C) 8 kg m/s
• D) 80 kg m/s

9. The blue tack hits another stationary lump of the same mass. They will stick together and move off at a velocity of..

1. 0.8 m/s
2. 8 m/s
3. 4 m/s
4. 16 m/s

10. When a racing car hits another car, a 'crumple zone' stops it decelerating too quickly and keeps the driver safe.

This 500kg car went from 8 m/s to zero in 0.2 seconds.

The force on the car was therefore...

1. 2000N
2. 2500N
3. 4000N
4. 20000N

F = change in momentum / time

11. The power of a runner or light bulb is measured in joules per second, or more commonly called

• A. watts
• B. joules
• C. volts
• D. newtons

The table below shows the power and energy transferred by some common kitchen appliances. What are the missing values?