[Yahya (OP)]

If Mass and energy are interchangeable, in the equation:
U=-GMm/r
Putting it under the dimensional test:
E=CEE/L
Thus E/L should equal to one: E/L=1 how that is possible? It can’t
be that energy is equivalent to length.
 c is just a constant, even if it is not the dimensional
analysis should be :
E=(E/C2 )(E/C2 )/L
E/c4 L should =1
or ET4 / L5 =1 how that is possible?

[Bored chemist]

Mass and energy are only interchangeable if you remember to multiply mass by a constant which has units of velocity squared.

If you rty again I think you will be able to get it to work.

[Yahya (OP)]

I tried putting G and it worked