What can be thrown, caught, and used to provide resistance for a variety of movements, in a variety of planes of motion, and at a variety of velocities?

Wish i knew this to !

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other

Mass and velocity are the 2 factors used to calculate kinetic energy. the equation for kinetic energy is (1/2)mv^2. hope this !