# Earth's Gravitational Force On Me

1. Nov 25, 2014

### Zack Davis

I am working on a problem to sate my own curiosity. :) My mass is approximately 85.1 Kg. The Earth's mass is approximately (5.972x10^24 kg) and the distance between our center of masses is roughly the same as the Earth's radius of (6371 km) so I was wondering; what would the earth's gravitational force be between the two of us. My answer is 8.3514...x10^8 N
(Using the formula:
F=G ( (m1xm2)/r^2) )
Am I correct? Thank you!

Last edited: Nov 25, 2014
2. Nov 25, 2014

### Staff: Mentor

Oh my, no. One kilogram is equal to about 9.8 newtons here on Earth, so you should be getting about 834 newtons, or 8.34x102. It looks like you've made some sort of order of magnitude error, but I can't be sure.

3. Nov 25, 2014

### Staff: Mentor

Hi Zack Davis. http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif [Broken]

Your answer is a little greater than expected. I was thinking more like 85.1x9.81 N

Did you convert distance to metres for that formula?

Last edited by a moderator: May 7, 2017
4. Nov 25, 2014

### Staff: Mentor

I bet that's it. 6,000 Km squared is 3.6x107, but 6,000,000 meters squared is 3.6x1013, a difference of 6 orders of magnitude, which is how far off his final value is.

5. Nov 25, 2014

### Zack Davis

I found the problem, I was acting as though I am a celestial body! Haha. Thank you all for the help!