Answer:
B. -900 kg-m/s2
Step-by-step explanation:
First of all, we need to calculate the acceleration of the hockey player, which is given by:

where
v = 12 m/s is the final speed
u = 18 m/s is the initial speed
t = 0.6 s is the time
Substituting into the formula, we find

And now we can calculate the force exerted by using Newton's second law:

where m=90 kg is the mass of the hockey player. Substituting into the formula, we find
