The equation that gives the potential energy of an object is given by:
[tex]U=mgh [/tex]
where
m is the mass of the object
g is the gravitational acceleration
h is the height above the ground
Using this equation, the potential energy of the first rock is:
[tex]U_1 = mgh=(20 kg)(9.81 m/s^2)(100 m)=19620 J[/tex]
while the potential energy of the second rock is:
[tex]U_2 = mgh=(20 kg)(9.81 m/s^2)(50 m)=9810 J[/tex]
So, the potential energy of the first rock is twice that of the second rock.
