AS Applied Science Unit 2
Assignment 3
1. What is momentum measured in?
2. Complete the table below
| Object | mass (kg) | velocity (ms-1) | momentum |
| dog | 15 | 8 | |
| car | 1,500 | 30 | |
| rugby player | 110 | 900 kg ms-1 | |
| bus | 6 | 42,000 kg ms-1 |
3. A minibus of mass 2,300 kg travelling at 20 ms-1 collides with a stationary mini of mass 900 kg. The two vehicles stick together.
a) Calculate the momentum of the minibus before the collision
b) State the total momentum after the collision. How do you know?
c) Calculate the velocity of the two vehicles immediately after
d) Calculate the total kinetic energy before and after the collision. Comment on your answer.
4. A man of mass 70kg jumps out of the window of a burning building 5m high.
a) Calculate his g.p.e. before he jumps
b) What will his kinetic energy be just before he hits the ground?
c) Calculate this velocity just before he hits the ground
d) Calculate his momentum just before he hits the ground
When he hits the ground ( concrete ) he comes to a complete stop in 0.1 seconds and breaks nearly every bone in his body.
e) Calculate the average force slowing him down
f) What could he do to reduce the force slowing him down? Explain your answer.
5. Explain the following;
a) A metal hammer is much better than a rubber hammer for banging in nails
b) When you catch a fat moving cricket ball you should move your hand with the ball as you catch it
c) If you saw the barrel of a rifle in half the bullets do not come out as fast.