Ball a of mass 5.0 kg moving at 20 meters per second collides with ball b of unknown mass moving at 10. meters per second in the same direction. after the collision, ball a moves at 10 meters per second and ball b at 15 meters per second, both still in the same direction. what is the mass of ball b

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.