Question

A hockey puck slides on ice (looking down on the ice from above; blue arrows are momentum, red line shows path); friction and air resistance are negligible. When the puck reaches location 2 it is struck hard by a hockey stick; the contact lasts a very short time. It then travels from 2 to 3 at nearly constant momentum. The magnitude of the puck's momentum is the same at locations 1 and 3. 

Which green arrow best indicates the direction of the force applied to the puck by the hockey stick? Assume the force was constant during the contact.

Answer 1

Force = ∆P / T = (Pf - Pi) / T

Force = Delta P/Delta t = P Vector_f - P Vector_i/Delta t = P j^Hat - p i^Hat/Delta t theta = tan^-1 P/P theta = 45 degree w.r.t x below Therefore arrow (6) best indicates the direction