The gymnast descends from position B and regains contact with the trampoline when it is in its unstretched position. At this position, her centre of mass is 3.2 m below its position at B. Calculate her kinetic energy at the instant she touches the unstretched trampoline

Question

The gymnast descends from position B and regains contact with the trampoline when it is in its unstretched position.  At this position, her centre of mass is 3.2 m below its position at B.  Calculate her kinetic energy at the instant she touches the unstretched trampoline

anonymous · Answer

According to energy conservation, mgh=1/2m(v^2)... That is kinetic energy is exactly equal to the value when he was at his highest position (3.2 metre above). 

Plug the values, g=9.8, h=3.2 , m= well this value is required , and calculate.