Elastic and Inelastic Collisions

6.3

Perfectly Inelastic Collisions• When two objects collide and move

with each other after.

Practice Problems 6E, 1-5, p. 224:1. A2. A3. A4. A5. a.

b.

Kinetic energy is not constant in inelastic collisions• KE converted to sound and internal

energy as objects deform.• Decrease in KE can be calculated

using 0.5mv2

Practice Problems 6F, 1-5, p. 226:1. a.

b.2. a.

b.3. a.

b.

Elastic Collisions• After collision:

– Two objects• Remain separate.• Remain same shape after collision.

– Both momentum and KE remain the same

• Most collisions are neither elastic nor perfectly inelastic.– Most objects in an inelastic collision

do not stick.– In near elastic collisions, objects lose

energy to internal energy and sound.

• KE is conserved in an elastic collision.• If purely elastic both p and KE remain

constant before, during, and after the collision.

Practice Problems 6G, 1-4, p. 229:

1. a.b.

2. a.b.

3. a.b.

4. a.b.