Impulse

Question 1

Is momentum a vector or scalar?

Answer 1

Momentum is a vector quantity.

Question 2

Determine the momentum of a:
68 kg person moving east at 9 ms-1
1400 kg car moving north at 20 ms-1
31 kg dog moving south at 2 ms-1

Answer 2

612 kgms^-1
28000 kgms^-1
62 kgms^-1

Question 3

A car has momentum of 20000 kgms-1. What would be the car's new momentum if:
its velocity was doubled
its velocity was tripled
its mass was doubled 
both its velocity and mass were doubled

Answer 3

40000 kgms^-1
60000 kgms^-1
40000 kgms^-1
80000 kgms^-1

Question 4

What is an impulse?

Answer 4

Impulse is a measure of how easy, or difficult, it is to change the momentum of an object.

Question 5

Derive the equation for impulse using Newton’s second law.

Answer 5

1) Δp = dp/dt p = mv
2) dp/dt = (d(mv))/dt
3) dp/dt = m(dv/dt)
4) dp/dt = ma

Question 6

State if momentum is an example of a scalar or vector.

Answer 6

Vector

Question 7

State if impulse is an example of a scalar or vector.

Answer 7

Scalar

Question 8

State the units for momentum.

Answer 8

kgms^-1

Question 9

How can impulse be found with a force time graph

Answer 9

Impulse can be found through calculating the area under a force - time graph.

Question 10

TRUE OR FALSE

1) The unit for impulse is Ns-1
2) Momentum can be thought of as a quantity that a moving object has: it is proportional to the amount of force required to change its motion.
3) Impulse is the same as the change in momentum.
4) Impulse is larger if the impact time is smaller.
5) Impulse is larger if the force applied is larger.
6) On a force-time graph, change in momentum is calculated as the area under the graph.

Answer 10

F
T
T
F
T
F