Question

A stone sphere of radius 7.00 m rests in a flat field. Relative to the ground, what is the gravitational potential energy of a 90.0-kg person sitting on the very top of the sphere?
a. 7.76 x 104 J
b. 1.23 x 104 J
c. 3.88 x 104 J

Answer 1

Answer:

(B)  1.23 x 10⁴ J

Explanation:

Given;

radius of the sphere, r = 7.0 m

diameter of the sphere, d = 2r = 14.0 m

mass of the person sitting on the sphere, m = 90.0 kg

The gravitational potential energy of the person is given by;

P.E = mgh

where;

g is acceleration due to gravity = 9.8 m/s²

h is the height above the ground level = d = 14.0 m

P.E = mgh

P.E = (90)(9.8)(14)

P.E = 12348 J

P.E = 1.2348 x 10⁴ J

Therefore, the gravitational potential energy of the person is 1.2348 x 10⁴ J