# What is the gravitational potential energy of a  4 kg object on a shelf  3/4 m  high?

$29.4 J$
considering the gravitational potential energy to be zero at the bottom of the shelf,we get the potential energy of the object to be $m g h = 4 \cdot 9.8 \cdot \left(\frac{3}{4}\right) = 29.4 J$