A 0.450-kg hockey puck, moving east with a speed of 5.25 m/s , has a head-on collision with a 0.850-kg puck initially at rest. Assuming a perfectly elastic collision, what will be the speed (magnitude of the velocity) of each object after the collision

Explanation:

Given that,

Mass of the hockey puck, m₁ = 0.45 kg

Initial peed of the hockey puck, u₁ = 5.25 m/s (east)

Mass of other puck, m₁ =  0.85 kg

Initial speed of other puck, u₂ = 0 (at rest)

Let v₁ and v₂ are the final speeds of both pucks after the collision respectively. Using the conservation of momentum as :

The coefficient of restitution for elastic collision is equal to 1.          

On solving equation (1) and (2) we get :

Hence, this is the required solution.

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it