An object weighing 15 Newtons is lifted from the ground to height of 0.22 meters What is the approximate increase in the object's gravitational potential energy?
Gravitational potential energy is given by the equation PE = mgh, where m is the mass of the object, g is acceleration due to gravity and h is the object's height above a reference point in meters.
The given weight of the object, 15N, is equal to mg so PE = weight x h.
The increase in potential energy is therefore (15N)(0.22m) = 33 Joules
The energy unit Joule is derived from kg x m/s^2 or Newton-meters.
Gravitational potential energy is the energy an object has due to its position. Since energy is conserved, an amount of work equal to 33 Joules had to be done on the object to lift it to this height. Work is the force applied to an object multiplied by the distance that the force moves it.