# Homework Help: What is the gravitational Field?

1. Sep 10, 2008

### grouchy

Hint: Use shell theorem and/or flux argument for a symmetrical shell.

A thin spherical shell has a radius of 3.4 m and a mass of 456 kg. The Universal gravitational constant is 6.6726 x 10^-11 N m^2/kg^2.

What is the gravitational field 1.4 m from the center of the shell? Answers in units of N/kg.

Attempt--
I tried this equations, a= - G(delta m)/ (x^2 + y^2)

2. Sep 10, 2008

### granpa

forget equations. picture the flux

3. Sep 10, 2008

### LowlyPion

The gravitational field is a vector field. The gravity at the center will be the integral of all the mass of the shell acting at that point through all directions.

http://en.wikipedia.org/wiki/Shell_theorem

4. Sep 10, 2008

### grouchy

5. Sep 10, 2008

### granpa

yip.

6. Sep 10, 2008

### grouchy

eh.. thanks lol! Need to pay attention in class a bit more :)

7. Sep 10, 2008

### LowlyPion

Correctamundo.

Good luck.

Study Tip: Read next week's problems before going to next week's class. Then you know what part of the lecture to snooze through.