Two objects have masses of #9 MG# and #5 MG#. How much does the gravitational potential energy between the objects change if the distance between them changes from #36 m# to #48 m#?

1 Answer

#GM_1M_2(\frac{1}{D_1}-1/D_2)#

Explanation:

Hint: In general, the gravitational potential energy #U# of two point masses #M_1# & #M_2# at a distance #D# between them is given as

#U=-\frac{GM_1M_2}{D}#

Hence, if the distance between the masses changes from #D_1# to #D_2# such that #D_2>D_1# then the change in gravitational potential energy #\Delta U# is given as follows

#\Delta U=U_2-U_1#

#=-\frac{GM_1M_2}{D_2}-(-\frac{GM_1M_2}{D_1}_#

#=GM_1M_2(\frac{1}{D_1}-1/D_2)#