A 0.200 kg air-track glider moving at 1.20 m/s bumps into a 0.600 kg glider at rest.
a.) Find the total kinetic energy after collision if the collision is elastic.
b.) Find the total kinetic energy after collision if the collision is completely inelastic.

a) 0.144J

b) 0.12J

Explanation:

A 0.200 kg air-track glider moving at 1.20 m/s bumps into a 0.600 kg glider at rest. a.) Find the total kinetic energy after collision if the collision is elastic. b.) Find the total kinetic energy after collision if the collision is completely inelastic.

Given that

M1 = 0.2kg

M2 = 0.6kg

U1 = 1.2 m/s

Since both momentum and energy are conserved in elastic collisions, the total kinetic energy after collision will be

1/2M1U^2 + 1/2M2U^2

1/2 × 0.2 × 1.2^2 + 0

K.E = 0.144J

B) In elastic collision, only momentum is conserved

M1U1 + M2U2 = (M1 + M2)V

U2 = 0 since the object is at rest

0.2×1.2 + 0 = (0.2 + 0.6)V

0.24 = 0.8V

V = 0.24/0.8

V = 0.3 m/s

K.E = 1/2(M1+M2)V

K.E = 1/2 (0.2 + 0.6) × 0.3

K.E = 0.4 × 0.3

K.E = 0.12J

second mirror gathers light from a faraway object and reflects it to another mirror. - a.