please check my answers. 17. explain how the sport of pole vaulting dramatically changed when flexible fiberglass poles replaced still wodden poles?

please check my answers. 17. explain how the sport of pole vaulting dramatically changed when flexible fiberglass poles replaced still wodden poles?-the fiberglass poles had more momentum and PE than still wooden poles?20. does the international space station have gravitational pe? ke? explain?-It has gravitation pe, but I am stuck as to why?25. what does the work theorem say about the speed of a satillite in circular orbit? (this one I dont understand)30.a moving hammer hits a nail and drives it into a wall. if the hammer hits the nail with twice the speed, how much deeper will the nail be driven? if it hits with three times the speed?-would it be three times the speed