Question

The potential energy of an object suspended 100 ft above the earth is known to be 10 J. What would be the potential energy (in joules) of a second object suspended 100 ft above the earth if the mass of the second object is twice the mass of the first object?

Answer 1

20 J

Step-by-step explanation:

Potential energy (relative to the earth) of the first object is the energy possessed by that object due to its height from the surface of the earth.

The PE of the first object is 10 J and it is given mathematically as:

`PE_1` = mgh

where m = mass of object

g = gravitational acceleration

h = height of object

If another object has twice the mass of the first object, but is at the same height (100 ft) as the object, that means mass, M, will be:

M = 2m

and the PE of the second object will then be;

`PE_2` = Mgh

`PE_2` = 2mgh

`PE_2` = 2 *
`PE_1`

`PE_2` = 2 * 10 J = 20 J

The Potential Energy of the second object is 20 J