- #1
Crush1986
- 207
- 10
Homework Statement
Mass M is distributed uniformly along a line of length 2L. A particle of mass m is at a point that is a distance a above the center of the line on it's perpendicular bisector. For the gravitational force that the line exerts on the particle. calculate the components perpendicular and parallel to the line. Does your result reduce to the correct expression as a becomes very large?[/B]
Homework Equations
[itex] F=\frac{GMm}{r^2} [/itex]
[itex] \lambda = M/L [/itex]
The Attempt at a Solution
So I've been trying to brush up on some first year stuff as I'm transferring to a four year next semester. I'm getting an answer that is too big by a factor of two, not sure why.
Solving for the perpendicular component of force. I have
[tex] \frac {aGmM}{L}\int_{-L}^{L} \frac{dx}{(a^2+x^2)^{3/2}} [/tex]
this gives me [tex] \frac{2GmM}{a(L^2+a^2)^{1/2}} [/tex] two times to big.
Where am I making the answer twice as big?[/B]