Question

A man carries a 12-kg chair up one flight of stairs to the second floor of his house. If the second floor is 3.3 m above the first floor, what is the change in the gravitational potential energy of the chair? a - 180 J b + 390 J c + 180 J d - 390 J e zero

Answer 1

Answer:

Change in gravitational potential energy of the chair is, $\Delta PE=390\ J$

Explanation:

It is given that,

Mass of the chair, m = 12 kg

Distance of the second floor from the ground, h = 3.3 m

The position of ground at h = 0

Let $\Delta PE$ is the change in gravitational potential energy of the chair. Initial potential f the chair is equal to 0.

$\Delta PE=mgh$

$\Delta PE=12\ kg\times 9.8\ m/s^2\times 3.3\ m$

$\Delta PE=388.08\ J$

or

$\Delta PE=390\ J$

So, the change in the gravitational potential energy of the chair is 390 joules.