A0.320 kg puck at rest on a horizontal frictionless surface is struck by a 0.220 kg puck moving in the positive x direction with a speed of 4.09 m/s. after the collision, the 0.220 kg puck has a speed of 1.29 m/s at an angle of θ = 60.0° counterclockwise from the positive x axis. (a) determine the velocity of the 0.320 kg puck after the collision. express your answer in vector form. vf = m/s (b) find the percent of kinetic energy lost in the collision.

16. a brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 n on him. the mass of the losing player plus equipment is 90.0 kg, and he is accelerating at 1.20m/s2 size 12{1 "." "20"" m/s" rsup { size 8{2} } } {} backward. (a) what is the force of friction between the losing player’s feet and the grass? (b) what force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? (c) draw a sketch of the situation showing the system of interest used to solve each part. for this situation, draw a free-body diagram and write the net force equation.