The gravitational potential energy is given by:

where m is the mass of the object, g is the gravitational acceleration (which is 9.8 meters per second per second) and h is the height.
In this case, we know that:
• The potential energy is 915 J
,
• The mass is 19 kg
Plugging these values and solving for h we have:

Therefore, the height of the object has to be 4.91 m