Question

if the gravitational potential due to the earth on its surface assumed to be zero,then gravitational potential at height 2R from surface will be(R:radius of the earth; g; acceleration due to gravity on earth surface

Answer 1

Answer:

-GmM/3R.

Explanation:

From the question we know that the gravitational potential at the surface is 0 hence, we get that the U1=0.The potential at the surface would have been given as U=-GmM/R, but in this case it is 0.

When the body is taken to a distance 2R from the surface so, the radius becomes (R+2R). So, the gravitational potential is U2=-GmM/3R. Hence, the change in the potential energy will be given as U2-U1. Which will be equal to  -GmM/3R -0 which on solving we will get that -GmM/3R.