With a gravity that is 2.4 x earth's gravity it would be interesting to see what kind of lifeforms would evolve....

if the density (composition) is the same, the gravity would be about 80 times greater. The reason is gravity is calculated based on the square of the diameter and the mass is based on the cube of it (assuming the same density). so, if a planet is x times larger in diameter, that makes the gravity x^5 times greater. The math:

g=Gmr^{2}

I Thought the formula for the force of gravity on Earth was

F=Gm/r

^{2}where m is the mass of the Earth.

This is because the force reduces the further you get away from the centre of the earth.

If a planet has a S times bigger radius than Earth the volume of the new planet is S

^{3} times bigger than Earth the surface is also S times further from the centre of gravity.

If M is the mass of the new planet which had the same density as Earth then

M = S

^{3}m

and F= GS

^{3}m/S

^{2}r

^{2}The expression S

^{3} / S

^{2} can be reduced just S

so F =GSm/r

^{2} where r is the radius of the Earth.

i.e just S times stronger force of gravity at the surface of the planet.