I need help with this kind of science

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?

Ben (55kg) is standing on very slippery ice when junior (25kg) bumps into him. junior was moving at a speed of 8 m/s before the collision and ben and junior embrace after the collision. find the speed of ben and junior as they move across the ice after the collision. give the answer in m/s. describe the work you did to get the answer.

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?