Gravitational Potential Energy The energy associated with the position of a mass above a reference in a gravitational field. The amount of capable work that a mass can accomplish due to its position in a gravitational field. m h GPE=mgh GPE=gravitational potential energy Potential Energy is a scalar quantity and is measured in Joules (J). g = 9.8 m/s 2 If the mass is below the reference, then h is negative. reference

Gravitational Potential Energy Change ΔGPE=GPE 2 -GPE 1 =mgh 2 -mgh 1 =mg(h 2 -h 1 )=mgΔh=WΔh h1h1 h2h2 A positive change in potential energy implies that the object gained potential energy and moved farther away from the reference. A negative change in potential energy implies that an object lost potential energy and the object moved closer to the reference. A negative potential energy implies that an object is below the reference.

Potential Energy Application h GPE=mgh The potential energy of the water can be converted to the kinetic energy of the water wheel. The rotating water wheel can be used to generate electricity or move objects. The amount of work the wheel can accomplish is equivalent to the potential energy of the falling water.