hm, then I guess use Gm(p)m(s)/r^2 = m(s)v^2/r
you know G, the gravitational constant, you know the mass of the Earth and satelite..
theen, since you don't know v OR r, you can use v = d/t, so
Gmp/r = (r/t)^2, solve for r. once you know r, find v, then KE.
Once I find out how to solve for one I'll know how to solve for both, so let's just deal with the 5 kg cart.
That statement is incorrect, you have to deal with both of them at the same time.
So think of them in terms of Energy,
1/2kx^2 = 1/2m1v1^2 + 1/2m2v2^2