### Bartleby the Scrivener

# Physics

If you are given the density and radius of planet X, how would you calculate

the acceleration of gravity on the surface of this planet?

If you are given the density and radius of planet X, how would you calculate

the acceleration of gravity on the surface of this planet?

Answered by
Rohit N #1034246

As we know

F=ma (here a=g)

F=GMm/r^2 (newtons law of gravitation)

Therefore equating both forces we get

g=GM/r^2 --------------(1)

As we know density(þ)=Mass(M)/volume

But earth is sphere therefore volume of earth is 4/3(pie)×r^3

Therefore mass(M)=þ×4/3(pie)r^3

Substituting value of Mass M in equation 1

Therefore

g=Gþ4/3(pie)r