Ahockey puck is sliding along the ice with nearly constant momentum ‹ 7, 0, 4 › kg · m/s when it is suddenly struck by a hockey stick with a force ‹ 0, 0, 2100 › n that lasts for only 7 milliseconds (7×10−3) s. what is the new momentum of the puck?

Pf = (7 , 0 , 18.7 ) kg.m/s

Explanation:

initial momentum (Pi) = ( 7 , 0 , 4 ) kg.m/s

force (F) = ( 0 , 0 , 2100 ) N

time interval (t) = 7 x 10 ^{-3} s = 0.007 s

find the final momentum (Pi) of the pluck

from the updated form of the momentum principle Pf = Pi + F(Δt)

where Δt is the same as the time interval

substituting all required values we have

Pf = ( 7 , 0 , 4 ) + [( 0 , 0 , 2100 ) x 0.007]

Pf =  ( 7 , 0 , 4 ) + ( 0 , 0 , 14.7 )

Pf = (7 , 0 , 18.7 ) kg.m/s

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be