[问答题]
Derive a formula for the mass of a planet indp68-5asi,gw(, ljobq1 vp o8vvu4ke terms of its r, *sayi,jeo+ d 60fc7blqymx v0cu2o8adius r, the acceleratio eu , fo*ay,c7+cvoyljmsb600x28qdin due to gravity at its surface and the gravitational constant G.
