# Free fall

1. Jan 20, 2010

### majormuss

1. The problem statement, all variables and given/known data

How can I find mass when weight and distance is given.(Note I can't use 9.8m/s^2 as my acceleration of gravity because the question is dealing distances that are extremely high from earth's surface.And also how can i find the right acceleration at such heights?

2. Relevant equations

F=ma

3. The attempt at a solution
am stuck cos I know i can't use 9.8m/s^2.

2. Jan 20, 2010

### Fightfish

Have you come across newton's theory of gravitation?
$$F_{g} = \frac{Gm_{1}m_{2}}{r^2}$$