- #1

Jimmy87

- 686

- 17

## Homework Statement

Use data from your experiment to support the idea that Young's Modulus relates the material and is independent of shape and geometry whilst the spring constant is a function of the shape and geometry. The experiment involved stretching identicle springs (starting off with one all the way to to 5) for series and parallel with a constant load of 1kg.

## Homework Equations

YM = FL/Ax (YM - youngs modulus, F - force, L - original length, A is area and x is extension).

spring constant = F/x

## The Attempt at a Solution

I was thinking that when they are in series as you add more springs the original length increases but in the same proportion to the extension. The area is and force are fixed so YM is constant. Is that correct? In parallel, as you add more springs the extension increases but the area decreases in proportional so that the product of Ax is constant. Force and original length are constant so again YM is constant. With the spring constant I guess F in this case refers to the force on each individual spring whereas F in the YM equation refers to the overall force otherwise I don't see how the spring constant can change (which it must do if it depends on shape/geometry). When relating to a spring what exactly is A? Is it the area of one coil or the cross sectional area?

Also, would I be right in saying that strain for the springs in series is constant but for parallel it isn't because the force is fixed in parallel but the area goes down as you add more springs? So is strain dependent on shape/geometry?

Thanks for any help