P5 - Momentum

Question 1

State the equation used to calculate an object’s momentum. (Higher)

Answer 1

Momentum = Mass x Velocity

Question 2

What is the unit used for momentum?

Higher

Answer 2

kg m/s

kilogram metres per seconds

Question 3

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

Answer 3

The total momentum before is equal to

the total momentum afterwards.

Question 4

State an equation linking change in

momentum, force and time. (Higher)

Answer 4

Force x Time = Change in Momentum

F Δt = mΔv

Question 5

What quantity is equal to the force

experienced in a collision? (Higher)

Answer 5

The rate of change of momentum.

Question 6

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

Answer 6

Increase the length of time over which

the change of momentum occurs.

Question 7

Explain how a seatbelt improves a
passenger’s safety during a collision.
(Higher)

Answer 7

● Passenger must decelerate from the vehicle’s velocity at impact
to zero, 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