Question

A book weighs 16 n and placed on a shelf that is 2. 5 m from the ground. What is the gravitational potential energy of the book

Answer 1

Answer: 40J

Explanation:

Gravitational potential energy is defined as the mass of the object, multiplied by the acceleration due to gravity, and the height from your arbitrary reference point. If we assume that the floor has a gravitational potential of zero, then the gravitational potential of the book on the shelf would be:

$U=mgh$

We were given the weight of the book, not the mass. In order to find the mass of the book, we need to divide the weight by the acceleration of gravity. We have that:

$Mass=Weight/Gravity$

$Mass=16N/9.8m/s^2$

$Mass=1.63kg$

Plug everything into the gravitational potential formula to get:

$U=(1.63kg)*(9.8m/s^2)*(2.5m)$

$U=40J$