Question

A hockey ball of mass 200g travelling at 10m/s is struck by a hockey stick so as to return it along its original path with a velocity at 5m/s.Calculate the change of linear momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.

Answer 1

Given :-

The mass of the hockey ball is = (m) = 200 g = 0.2 kg

[ as 100-g = 1 kg ]

Initial velocity (u) = 10 m/s

Final velocity (v) = -5 m/s

 

[ final velocity of the ball is in the direction opposite to the direction of the initial velocity ]

 

To be found :-

The change of linear momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.

 

The change of momentum of the ball

= Final momentum - Initial momentum

= mv - mu

= m(v -u)

= 0.2(-5 - 10)

= 0.2(-15)

= -3 kg - m/s

Hence,

The change of linear momentum occurred in the motion of the hockey ball by the force applied by the hockey stick is -3 kg - m/s.

Answer 2

Explanation:

mv - mu

m(v-u)

0.2 ( -5 -10)

0.2(-15)

-3kg m/s