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A 75-kilogram hockey player is skating across the

ice at a speed of 6.0 meters per second. What is

the magnitude of the average force required to

stop the player in 0.65 second?

(1) 120 N (3) 690 N

(2) 290 N (4) 920 N

Verified Answer :

Giovi

I think it is (3) 690 N. You can use the theorem of Impulse and momentum where the impulse is equal to the change in momentum or:
\(F \Delta t=m v_{f}-m v_{i}\) (where f is for final and i for initial).
So you get:
\(F*0.65=0-(75*6)\)
\(F=692 N\)