Spring problem-perpendicular force

1. Nov 17, 2008

racast5

okay so i need help with the problem because my teacher gave it to us today and he doesnt teach the class anything.
it regards a body suspended in between two vertical springs, each in equilibrium, with length L.
he asked us to calculate the amount of required force to pull the body horizontally as if along the x axis, with regards to the angle (theta) with would be created by the initial vertical position of the spring and the new position. THEN he asked us to use a taylor series to show him, something, if anyone has any ideas what that series could prove..help? thanks
i just dont know where to start because he never explained the relations when more than one spring is involved, nor pulling them horizontally with a taylor series proof that that matter. the only equation i know is hooks equation f=-kx

2. Nov 18, 2008

tiny-tim

Welcome to PF!

Hi racast5! Welcome to PF!

You can still use Hooke's law …

the force will still be kx, where the x is the new length of the spring minus its original length …

in other words, you have a thin right-angled triangle, and x is the difference in length between the hyptoneuse and the side.

Since this will be √(1 + something), you can use a Taylor series to approximate it.

3. Nov 18, 2008

devon cook

I still can't get a reply from anyone. Who is out there?????
Dev

4. Nov 18, 2008

tiny-tim

the mother-ship has left us …

There is no-one out there …

we are all alone!

5. Nov 18, 2008

devon cook

You may be right TT. You may be right. Anyway, it's good to make some sort of contact at last. I've been playing around with the maths of a frictionless bead sliding down a parabola y=0.5(x-1)^2 . I got a messy result for its velocity but can't get the same using Hamiltonian mechanics. Anyone done this?
Dev

6. Nov 19, 2008

tiny-tim

Welcome to PF!

Hi Dev! Welcome to PF!

I'm no good at Hamiltonian mechanics.

You'd better start a new thread (press the NEW TOPIC button on the sub-forum index page), and put the question there (title it "Hamiltonian mechanics").

(that's because hardly anyone new will look at a thread once it's had several replies … which, incidentally, is a good reason not to "bump" your threads)

7. Nov 20, 2008

devon cook

Thanks TT,
But I can't find the "sub-forum index page" anywhere.
Dev

8. Nov 20, 2008

click!

Hi Dev!