# physics

posted by
**Kelly K.**
.

Two 0.55 kg basketballs, each with a radius of 15 cm, are just touching. Ignore any other gravitational interactions.

(a) How much energy is required to change the separation between the centers of the basketballs to 1.0 m?

(b) How much energy is required to change the separation between the centers of the basketballs to 10 m?

Our teacher has not even talked about this and the chapter that we are working on deals with gravitational force and G. Can anyone tell me an equation to use or a theory? thank you

The gravitation energy will be

assuming you know calculus...

INT force*distance

INT GMM/x^2 dx = GMM/x eval at changes.

Energy= G(.55)^2 ( 1/.15 - 1/d) where d is the new separation.

If you don't understand the calculus involved, just use the result.

I used (2/3)x10^-10 for G and got1.14e-10. This assignment is on-line, so I get instant feed back and this answer was incorrect.