Question

What is the gravitational potential energy of a `9 kg` object on a shelf `8/9 m` high?

Answer 1

I tried this:

Explanation:

Gravitational Potential Energy `U` is energy stored by our system in doing work against the gravitational force (or Weight, `W=mg`) lifting an object to a certain height `h` with respect, say, the ground taken as zero reference.
We get:

`W=mgh=cancel(9)*9.8*8/cancel(9)=78.4J`