4.5.7.3 Changes in Momentum

Question 1

What happens when a force acts on a moving object?

Answer 1

when a force acts on an object that is moving, or able to move, a change in momentum occurs

Question 2

What effect does impact time have on the impact force?

Answer 2

the longer the impact time, the more the impact force is reduced

Question 3

What is the combined velocity following a collision where 2 trolleys are moving towards each other?

Answer 3

0m/s due to conservation of momentum

Question 4

When can momentum be extremely dangerous?

Answer 4

rapid changes in momentum lead to huge forces applying and these can be extremely dangerous

Question 5

How can you reduce the dangers of changes in momentum?

Answer 5

can reduce that danger if we make the change in momentum happen over a longer period of time

Question 6

What do car manufacturers use crash tests for?

Answer 6

car manufacturers use crash tests to design safety features such as seatbelts

Question 7

What happens during a car crash?

Answer 7

• during a car crash the momentum of the passengers falls from a large amount to 0 in less than a second
• this places huge forces on the passengers and that can be lethal

Question 8

How do you calculate the change in momentum?

Answer 8

Question 9

Why are safety features useful?

Answer 9

safety features such as: air bags, seat belts, gymnasium crash mats, cycle helmets and cushioned surfaces for playgrounds are important as the they increase the impact time the more the impact force is reduced which means the change in momentum occurs over a longer period of time