You weigh 716 newtons on Earth. You

travel to a newly discovered planet,

Planet X. Planet X has a mass that is 3

times that of Earth, but it also has a

radius that is twice as large. What is

your new weight in newtons on planet

x?

537 N

Explanation:

The force due to gravity of a planet is:

F = GMm / r²

where G is the universal gravitational constant

M is the mass of the planet

m is the mass of the object

and r is the distance between the object and the center of the planet

On Earth, you weigh 716 N, so:

716 N = GMm / r²

On planet X:

F = G (3M) m / (2r) ²

F = 3/4 GMm / r²

F = 3/4 (716 N)

F = 537 N