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.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.