Posted by **Kylie** on Sunday, January 2, 2011 at 4:51pm.

Assume a planet is a uniform sphere of radius R that (somehow) has a narrow radial tunnel through its center. Also assume we can position an apple anywhere along the tunnel or outside the sphere. Let FR be the magnitude of the gravitational force on the apple when it is located at the planet's surface. How far from the surface (in terms of R) is there a point where the magnitude of the gravitational force on the apple is 1/7FR if we move the apple (a) away from the planet and (b) into the tunnel?

I have no idea how to start this question please help!

## Answer this Question

## Related Questions

- Physics - Planet Earth as a Spring. Assume that the Earth is perfect sphere of ...
- Circle geometry! - A circular tunnel, 20 m in diameter is blasted through a ...
- physics - Imagine a frictionless perfectly straight tunnel which runs from ...
- physics - Imagine a frictionless perfectly straight tunnel which runs from ...
- physics - Why do you lose weight when you enter a tunnel passing through a ...
- physics - a train goes into a tunnel at 20m/s and emerges from itat 55m/s. the ...
- physics - Assume that the Earth is spherical and recall that latitudes range ...
- physics - Assume that the Earth is spherical and recall that latitudes range ...
- physics - Suppose a spherical planet P has a uniform density of 4.96*10^3 kg/m^3...
- Math - An igloo approximates a hemisphere, with an entrance tunnel that ...