# How does the extension of one spring compare with the extension of two, three and four in parallel?

G.C.S.E Coursework- Springs

Aim

How does the extension of one spring compare with the extension of two, three and four in parallel?

## Prediction

From Hooke’s law, which states that “the extension of a spring is directly proportional to the load, provided that elastic limit is not exceeded” I predict that the more springs that are in parallel the less the extension will be. If a spring has a load of 1N it will have a certain extension. (x) Two springs in parallel will share the 1N load so each will feel 0.5N. The extension the extension for each one of them will be half the extension for one spring on its own. (x/2) Three springs in parallel will also share 1N load only each one this time will feel 0.33N, and each of their extensions will be one third of what it would be for one spring. (x/3) Finally four springs in parallel sharing the 1N load will each have an extension for one spring. (x/4) This because each feel only 0.25N of the 1N load.

Equipment List

Here is a list of equipment, which I will need to carry out this experiment: -

• Retort stand
• Clamp
• Boss
• Springs (4)
• Hanger
• 1N weights (5)
• Metre ruler
• Safety glasses

Diagram

Method

1. Set up equipment as shown
2. Put on safety glasses in case any springs snap
3. Measure the original length of one spring and hanger
4. Add a 1N weight and measure the new length
5. Repeat this until the total weight on the spring is 5N
6. Take the original length from the new length and record the extension
7. Move the metre ruler to change the scale from which you are measuring from
8. With the new scale repeat points 3-6 two more times
9. Take an average for each load which is added (0-5N)

10. Repeat points 3-9 for two, three and four springs in parallel

Variables

To make the results fair I will have to control some of the variables and keep them the same. I will have to keep the metre ruler the same at every measurement in case the scale is different, on a different ruler. Also I will need to use the same hanger on each of the sets of parallel springs. I need four springs at one point, but to keep it a fair test all four of these springs will have to be of the same type. ...