Question

A rock weighing 98 newtons is pushed off the edge of a bridge 50 meters above the ground. What was the potential energy of the rock before it began to fall?

Answer 1

Ep = 4900 because Ep = wh

Answer 2

Answer: The potential energy of the rock before it began to fall is 4900 J

Step-by-step explanation:

Force is defined as the mass multiplied by the acceleration of the object.

`F=mg`

where,

F = force exerted on the object

m = mass of the object

g = acceleration due to gravity

Potential energy is defined as the energy possessed due to the height of the object.

Mathematically,

`E_p=mgh`

Or,

`E_p=F* h`

where,

`E_p` = potential energy of the rock = ?

F = force applied on the rock = 98 N

h = height of the bridge from where the rock is thrown = 50 m

Putting values in above equation, we get:

`E_p=98N* 50m\\\\E_p=4900J`

Hence, the potential energy of the rock before it began to fall is 4900 J