ODU: Collisions, explosions and impulse

Question 1

Priniciple of conservation of momentum

Answer 1

The total momentum before an interaction is equal to the total momentum after the interaction, proving there are no external forces acting on the objects.

Question 2

Inelastic collision

Answer 2

A collison in which momentum is conserved but kinetic energy is lost.
Some of the kinetic energy is converted into heat and sound upon impact.

Question 3

Elastic Collsion

Answer 3

A collision in which both momentum and kinetic energy is conserved

Question 4

Impulse

Answer 4

The product of force and time. It is a vector quanity. It is also equal to the change in momentum of an object and is given by the area under a force-time graph.

Question 5

Airbags.

Answer 5

Found in vehicles as a safety feature.They increase the time taken for a person’s head to decelerate to rest on impact with the steering wheel, thereby reducing the average force exerted on the person’s head

Question 6

Crumple zones

Answer 6

Found at the front and rear of vehicles as a safety feature.
They increase the time taken for the vehicle to decelerate to rest on impact,thereby reducing the average force exerted on the passengers.