What is the force of gravity on a space craft $12,800$ km above the Earth$’$s surface if its mass is $1400$ kg$?($G $=6\mathrm{.}67$ x $10^-$¹¹ m$\mathrm{³}/$kg$\bullet$s$\mathrm{²},$ the mass of the Earth is $5\mathrm{.}972$ times $10\mathrm{ 2}4$ kg$,$ and the radius of the Earth is $6\mathrm{.}371$ x$10\mathrm{⁶}$ m$)$