The potential energy is most often referred to as the "energy at rest" and is dependent on the elevation of an object. This can be calculated through the equation,
E = mgh
where E is the potential energy, m is the mass, g is the acceleration due to gravity, and h is the height. In this item, we are not given with the mass of the cart so we assume it to be m. The force is therefore,
E = m(9.8 m/s²)(0.5 m) = 4.9m
Hence, the potential energy is equal to 4.9m.
