R = 8*10^6 m
m = 1 kg
P = 5 N
P = mg = GM/R^2, where g is the acceleration of the gravity, M is the mass of the planet, G=6.67*10^-11 m^3/(kg*s^2) is the gravitational constant.
Thus, g = P/m = 5 m/s^2,
M = gR^2/G = 4.8*10^24 kg.
Average density is rho = M/V, where V = 4/3*pi*R^3 is the volume of the planet.
rho = 3g/(4*pi*G*R) = 2200 kg/m^2.
who can tell me the mass, acceleration of gravity,and avg. density in this situation?