Question

A 2.74 g coin, which has zero potential energy at the surface, is dropped into a 12.2 m well. After the coin comes to a stop in the mud, what is its potential energy with respect to the surface?

A. 0.544 J
B. -0.328 J
C. 0.356 J
D. -0.165 J

Answer 1

B. - 0.328

Step-by-step explanation

Potential Energy: This is the energy of a body due to position.

The S.I unit of potential energy is Joules (J).

It can be expressed mathematically as

Ep = mgh........................... Equation 1

Where Ep = potential energy, m = mass of the coin, h = height, g = acceleration due to gravity,

Given: m = 2.74 g = 0.00274 kg, h = 12.2 m, g = 9.8 m/s²

Substituting these values into equation 1

Ep = 0.00274×12.2×9.8

Ep = 0.328 J.

Note: Since the potential energy at the surface is zero, the potential Energy with respect to the surface = -0.328 J

The right option is B. - 0.328