What is the gravitational Field?

[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)

 

[granpa]

forget equations. picture the flux

 

[LowlyPion]

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)

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.

Maybe read up a little about the Shell Theorem?
http://en.wikipedia.org/wiki/Shell_theorem

 

[grouchy]

wait..is the answer zero?

 

[granpa]

yip.

 

[grouchy]

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

 

[LowlyPion]

wait..is the answer zero?

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.