- #1
kraigandrews
- 108
- 0
Homework Statement
A massive ring (radius = a and mass = M) lies on the xy plane. Calculate the force F on a test mass m at position z on the z axis.
Now assume a = 1 and GMm/a2 = 1 in some system of units.
(a) What is the force on m at z = 0?
I got the answer for this its 0
(b) What is the force on m at z = a?
the answer for this is 0.354
(c) What is the maximum force on m ?
I am stuck on this one.
Homework Equations
F=(GMm)/r^2
The Attempt at a Solution
after some work I get F=(2GmMx)/(x^2+a^2)^3/2
i know this is right because i got part b from it, however i don't Know how to find the maximum, my gut feeling is take the derivative with respect to x and set it equal to zero and then solve for x and plug back into F