An athlete is running at a constant velocity with a javelin held in his right hand. the force he is applying on the javelin as he carries it is 5.0 newtons. if he covers a distance of 10 meters, what work has he done on the javelin?

-- Since our athlete is running at constant velocity, AND the javelin is
staying with him, the speed of the javelin itself must also be constant. 

-- Therefore, the force of 5N that he's applying to the javelin can't possibly
be in the direction that he and the javelin are moving, otherwise the javelin
would be accelerating. 

-- So we know that the force is perpendicular to the javelin's motion ... like
probably straight up to prevent it from falling to the ground.

-- Since none of the force is in the direction the javelin is moving, the force
does no work on the javelin.  Zero.

I'll do it rn and then answer