5.7 Momentum

Question 1

What is the equation for momentum? (1)

Answer 1

Momentum (kgm/s) = mass (kg) x velocity (m/s)

Question 2

What is meant by conservation of momentum? (1)

Answer 2

The total momentum before an event is equal to the total momentum after an event in a closed system.

Question 3

When does force cause a change in momentum? (1)

Answer 3

When a force is applied to an object that is moving, or able to move, a change in momentum occurs.

Question 4

What is the equation for change in momentum? (1)

Answer 4

Force (N) = change in momentum (kgm/s) / change in time (s)

f = m(∆v) / ∆t

Question 5

What is equal to the force experienced in a collision? (1)

Answer 5

The rate of change in momentum

Question 6

If an object’s change in momentum is fixed, what can reduce the force that the object experiences? (1)

Answer 6

Increasing the length of time taken for the momentum to change.

Question 7

How are seatbelt’s designed to improve passenger safety? (1)

Answer 7

• Stretch slightly to extend the time over which force is applied
• so passenger’s momentum has time to reach zero
• and reduce force on them in collision.