mass of the hockey player m1 = 90 kg
mass of puck m2 = 0.150 kg
puck velocity v1= 45 m/s
distance traveled by puck to reach the goal =15.0 m.
now accoding to momentum conservation law
90×45+0.15×v2 = 0 [ since, If both are initially at rest and if the ice is frictionless,]
therefore, v2= -0.0725 m/s.
Now time taken by the puck to reach the goal
t= 15/45 = 1/3 sec.
therefore, how far does the player recoil in the time
=0.0725×1/3= 0.0241 m.