What is the potential energy of an apple that is 3m high
and has a mass of 0.5N?

Potential energy  =  (mass) x (gravity) x (height)

Divide each side by (G x H) :      Mass  =  PE / (G x H)  

PE = 6 joules

Gravity = 9.8 m/s

Height = 3 m

                                                    Mass  =  6 / (9.8 x 3) =

                                                                    6 / (29.4)  =  0.204 kg

                                 (weighs about 2 newtons or 7.2 ounces on Earth)

56 moles of   lieter in chemistry