A crane lifts a body of mass 132 kilograms to a height of 20 metres. Find the increase in the body’s gravitational potential energy. Consider the acceleration due to gravity 𝑔 to be equal to 9.8 metres per square second.
Remember, gravitational potential energy represents the potential an object has to do work as a result of being located at a particular position in a gravitational field. The formula we use for gravitational potential energy, which is measured in joules, is mass multiplied by acceleration due to gravity multiplied by height. In this question, the crane is lifting a body of mass 132 kilograms. We multiply this by acceleration due to gravity, which is 9.8. And the height of the object is 20 metres.
We set the starting height of the object equal to zero. And so the increase in the body’s gravitational potential energy’s change will be 132 times 9.8 times 20, technically, minus zero, although of course we don’t need to subtract zero. 132 multiplied by 9.8 multiplied by 20 is 25872. And so the increase in the body’s gravitational potential energy is 25872 joules.