9.4- ELASTIC AND INELASTIC COLLISIONS

Question 1

What is an elastic collision?

Answer 1

elastic collision in one where there’s no less of kinetic energy

Question 2

If there’s a very low speed impact between two cars, would it be almost perfectly elastic or inelastic collision?

Answer 2

almost perfectly elastic, provided no damage done

Question 3

What is an inelastic collision?

Answer 3

inelastic collision occurs where colliding objects have less K.E. after collision than before the collision

Question 4

What sort of collision do objects that collide and couple together undergo?

Answer 4

inelastic collisions

Question 5

Why do objects that collide and couple together undergo inelastic collisions?

Answer 5

some of the initial KE transferred to surroundings

Question 6

To work out whether a collision is elastic or inelastic, what must be calculated?

Answer 6

KE of each object before + after collision

Question 7

For a ball of mass m falling in air from a measured height H above the floor + rebounding to a height h, what is the KE immediately before impact?

Answer 7

KE energy immediately before impact = loss of potential energy through height H =mgH

Question 8

For a ball of mass m falling in air from a measured height H above the floor + rebounding to a height h, what is the KE immediately after impact?

Answer 8

KE immediately after impact = gain of potential energy through h = mgh

Question 9

For a ball of mass m falling in air from a measured height H above the floor + rebounding to a height h, what does the ratio h/H give?

Answer 9

height ratio h/H gives fraction of initial KE that’s recovered as KE after collision

Question 10

For collision between two objects, how can KE of each object be worked out?

Answer 10

using KE equation = 1/2mv^2