How much gravitational potential energy does a five KG rock have a good is sitting on the edge of a cliff that is 10 m high?

Potential energy = mgh

m = mass (5 kg), g = gravity (9.8 m/s^2)

And h = height (10m)

Plug in those numbers

Potential energy = (5)(9.8)(10) = 490

490 J

a is the best answer your welcome

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.