Question

You release a 0.57 kg basketball from a height of 10 m. Neglecting air friction, when the ball is 5 m from the ground, its ______ will be ______. A. kinetic energy; 0 J B. potential energy; 5 J C. kinetic energy; 27.9 J D. potential energy; 55.9 J

Answer 1

The original potential energy is given by

`E_(potential)=mgh=0.57 *9.8 *10=55.9J`
When it's 5m from the ground, part of the original potential energy is now kinetic energy.
The potential energy is now

`E_(potential)=mgh=0.57 *9.8 *5=27.9J`
and the kinetic energy is the original energy minus the current potential energy
55.9J-27.9J=27.9J
Answer C is the correct one.