A 60 kg runner has 1500 J of kinetic energy. How fast is he moving?

Place me with this question is my last question

The radius of an atom is closest in size to a

Consider an ideal gas at 27.0 degrees celsius and 1.00 atmosphere pressure. imagine the molecules to be uniformly spaced, with each molecule at the center of a small cube. what is the length l of an edge of each small cube if adjacent cubes touch but don't overlap?