Question

Rocks A and B are located at the same height on top of a hill. The mass of rock A is twice the mass of rock B. How does the potential energy of rock B compare to that of rock A?
A. Rock B has the same potential energy as rock A.
B. Rock B has one-quarter the potential energy of rock A.
C. Rock B has one-half the potential energy of rock A.
D. Rock B has twice the potential energy of rock A.

Answer 1

Answer:

Option C

Explanation:

Let the potential energy of rock A be represented as Pa

And the potential energy of rock B be represented as Pb

Pa = ma * g * h

Pb = mb * g*h

ma = 2 * mb

Thus, Pa = 2 mb * g*h

Pa/Pb = 2 mb * g*h/mb * g*h

Pa/Pb = 2

Pa = 2 * Pb

The energy pf rock A is two times the energy of rock B.

OR

Pb = Pa/2

Hence, option C is correct