A hockey 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