Gravitational Potential Energy - Practice Questions & MCQ

It is the amount of work done in bringing a body from    to that point against gravitational force.

• It is Scalar quantity

• SI Unit: Joule

• Dimension :

• Gravitational Potential energy at a point

             If the point mass M is producing the field

             

         Then gravitational force on test mass m at a distance r from M is given by

        And the amount of work done in bringing a body from to r

                   =

         And this is equal to gravitational potential energy

               So

gravitational potential energy 

Mass of source-body

mass of test body

distance between two

Note- U is always negative in the gravitational field because Force is attractive in nature.

  Means As the distance r increases U becomes less negative 

I.e U will increase as r increases

And for , U=o which is maximum

• Gravitational Potential energy of discrete distribution of masses

  

Net Gravitational Potential Energy

The distance of masses from each other

 

• Change of potential energy

if a body of mass m is moved from  to

Then Change of potential energy is given as

 

 

change of energy

distances

If  then the change in potential energy of the body will be negative.

              I.e To decrease potential energy of a body we have to bring that body closer to the earth.

• The relation between Potential and Potential energy

As

But

So

Where Potential

Potential energy

distance

 

• Gravitational Potential Energy at the center of the earth relative to infinity

           

           

                mass of body

             Mass of earth

 

• The gravitational potential energy at height 'h' from the earth's surface

Using

 

 

 The potential energy at the height

Radius of earth