a hockey ball of mass 200g , travelling from west to east, at 10 m/s is struck by a hockey stick . as a result the ball gets turned back and now has the speed of 5m/s the ball and the hockey stick were in contact for 0.20s

a) calculate the initial and the final momentum of the ball

b) state the direction of motion in each case

c) calculate the rate of change of the momentum of the ball

d)what are the SIunnits of a) momentum of the ball

e) calculate the force exerted by the hockey stick .on the ball and state its direction

c)

Given:

u = 10 i

v = -5 i

⇒ Initial momentum = mu = 2 i ( along the east direction)

Final momentum = mv = -i ( along west direction)

Rate of change of momentum = [Final momentum - Initial momentum]/ time = [-i - (2i)]/0.2 = -15i ( along west direction)

SI unit of momentum is kg m/s.

Force = Rate of change of momentum = 15N (along west direction)

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