this should be obvious, but I'm a little confused. Question is, ' If an object weight 100 pounds on the earths surface (4k miles from the center), is moved to 4000 miles above the surface. How much does it weigh?'(adsbygoogle = window.adsbygoogle || []).push({});

f=Gm1m2/r2, so you would square the r, which means you would divide Gm1m2 by 4 correct? So 25 pounds?

2.) An object on the surface of earth that weighs 100 pounds is moved to a planet with 5x the radius and that is 2x as large, how much does the object weigh?

so it would be Gm_{1}m_{2}/r^{2}= 100 lbs.

G(2)m_{1}m_{2}/5^{2}= 2/25 = 1/12.5.-- 100 * 1/12.5 = 8 lbs.

right?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Need some quick physics 110 help

**Physics Forums | Science Articles, Homework Help, Discussion**