4.5.7 momentum (will come up) P2

Question 1

Unit for momentum

Answer 1

kg m/s

kilogram metres per second

Question 2

In a closed system, what can be said about the momentum before and after a collision

Answer 2

The total momentum before is equal to the total momentum afterwards

Question 3

What quantity is equal to the force experienced in a collision

Answer 3

The rate of change of momentum

Question 4

If an object’s change of momentum is fixed, what is the only way to reduce the force that the object experiences

Answer 4

Increase the length of time over which the change of momentum occurs

Question 5

Explain how a seatbelt improves a passengers safety during a collision

Answer 5

Passenger must decelerate from the vehicles velocity at impact to 0, meaning they undergo a fixed change of momentum
The force they experience is equal to the rate of change of momentum
Seatbelts increase the time over which the force is applied, reducing the rate of change of momentum and therefore reducing the force experienced