# Gravitational related problem

1. Oct 30, 2005

### elle

Last edited by a moderator: Apr 21, 2017
2. Oct 30, 2005

### Tide

You know what r is in both cases so just use the formula to express F and F' for both cases and compare the two results.

3. Oct 30, 2005

### elle

I still don't understand...where does R come into the formula?? :uhh:

4. Oct 30, 2005

### Tide

r is the distance between the center of the Earth and the object in question. That is the symbol people usually use but I just noticed the picture you showed uses "d" to represent that distance so r is the same as your d.

5. Oct 30, 2005

### elle

Ok please bear with me if I sound dumb...never taken physics before so I'm finding it realli difficult
So do I have to find m1 and m2? And for G I've been given an approximation for it, and I dunno if I'm suppose to use it

6. Oct 30, 2005

### Tide

Assuming that neither the mass of the plane nor of the Earth change then they both cancel out - along with G! They made it really convenient for you. :)