Weight when mass and distance from Earth's center both double

[Bensky]

[SOLVED] Quick question on universal gravitation - I think I'm right - need clarifica

Homework Statement

What would happen to the weight of an object if its mass was doubled while its distance from the center of the Earth was also doubled?
a) The weight would double.
b) The weight would be quadrupled.
c) The weight would be cut in half.
d) The weight would be unchanged.

Homework Equations

F=Gm1m2/d^2

The Attempt at a Solution

F_new=2(Gm1m2)/(2^2)r^2
F_new=2/4=1/2

Therefore, the weight would be halved. (C)

Am I right in how I figured this out? I only have one chance to get this problem right, so I wanted to make sure the way I'm doing this is correct.

 

[Dick]

That's exactly right.

 

[Doc Al]

Looks good to me!

 

[Bensky]

Thanks, I got the problem right...if someone could lock this that would be nice.