posted by Ali .
How much work does it take to raise a 3kg object 5m into the air?
(a) What is the potential energy of the object when it is 5m in the air? (b) What does this tell you about the potential energy you get when you do work to lift an object?
(c) If you drop the object, how fast is it going when it hits the ground? (d) What is the object’s kinetic energy when it hits the ground?
(e) Compare your answers to parts (b) and (d). What happens to the potential energy the object had?