# You are a tourist on space odyssey; at what altitude above the surface

1. Dec 15, 2011

### jasonbans

1. The problem statement, all variables and given/known data
You are a tourist on space odyssey; at what altitude above the surface of earth will your weight be one-half your weight on the surface? express your answer as a mutiple of earth's radius rE

2. Relevant equations
Fg= GMm/r^2

3. The attempt at a solution
not sure how to do it

2. Dec 15, 2011

### PeterO

Re: Gravitation

Do you mean your actual weight or your apparent weight? Remember the apparent weight of people on the space station is zero as they are in free fall, but their actual weight is around 90% of their weight on earth - because there g ~ 8.9 rather than the 9.8 on the surface.

3. Dec 15, 2011

### jasonbans

Re: Gravitation

actual weight

4. Dec 15, 2011

### PeterO

Re: Gravitation

Look at your formula and consider what change can be made to halve the force.

I don't think you can change G - is is after all the Universal Gravitational Constant.

M won't alter - mass of the Earth

You could halve m if you put the passenger on a diet, but I don't think that is feasible.

Doesn't leave much else - and remember R is the distance from the centre of the Earth, so we are already one earth radius away when standing on the surface.