Question

Please help me solve...
P and Q are two points at distance x(x>R,radius of the Earth) and 2x respectively from the centre of the Earth.The gravitational potential at P is -800kj/kg.What is the work done to take a 1kg mass from P to Q?

Answer 1

@Abhisar

Answer 2

Have you tried it urself ?

Answer 3

What is the answer given ?

Answer 4

400 i think...

Answer 5

400kj

Answer 6

\(\sf \huge U=\frac{-GmM}{r}=\large Potential\times mass ~of~the~object\)
Since mass of the object=1, potential in this case will be equal to potential energy.


Now, potential at point P is -800kj, potential energy stored in the object of mass 1 kg will be -800kJ.

Also potential energy of the same object at point Q will be -800/2=-400kj.

Now work done in bringing the object from P to Q will be equal to the energy difference i.e
-400-(-800)=400kj

Answer 7

Got it ?

Answer 8

Ya...got it...

Answer 9

Great !