Gravitational Potential
 

Gravitational Potential problem 21


    • Define gravitational potential at a point.


    • Starting from the equation for the gravitational potential due to a point mass, show that the gravitational potential energy of a point mass at a distance from another point mass is given by




      where is the gravitational constant.


  • The figure below shows the path of a comet of mass as it passes around a star of mass .




    At point X, the comet is from the centre of the star and is moving at a speed of . At point Y, the comet passes its point of closest approach to the star. At this point, the comet is a distance of from the centre of the star. Both the comet and the star can be considered as point masses at their centres.


    • Calculate the magnitude of the change in the gravitational potential energy of the comet as it moves from position X to position Y.


    • State, with a reason, whether the change in gravitational potential energy in (b)(i) is an increase or a decrease.


 

main author and content editor: Noble Menedi Firima