A 0.21 kg hockey puck is sliding on a frictionless ice surface with a velocity of 14 m/s toward the east just before making contact with a hockey stick. Take east to be the +x direction. What change in momentum, including sign, does the puck undergo while in contact with the stick if just afterward the velocity of the puck is (a) 25 m/s toward the east, (b) 8.0 m/s toward the east, and (c) 12 m/s toward the west? (a) Number i Units (b) Number i Units v (c) Number i Units v