Answer:
The gravitational potential energy of the sphere would be reduced to
of the initial value.
Step-by-step explanation:
Near the surface of the Earth, the gravitational field is approximately uniform. The gravitational field strength is approximately
.
In a uniform gravitational field, the gravitational potential energy (GPE) of an object relative to the ground is proportional to height. For example, if an object of mass
is at a height
above the ground, the GPE of this object would be
relative to the ground.
In this example, the height of the sphere is reduced to
of its initial value. As a result, the GPE of this sphere relative to the ground would also be reduced to
of the initial value.