Investigate the factors which will effect the stretching of a Helical Spring when put under a load.

If the experiment is correctly done, the law should show to be true.

Prediction: I predict that the greater the weight applied to the spring, the further the spring will stretch. This is because extension is proportional to load and so if load increases so does extension and so stretching distance.

Equipment:

• 25swg Copper
• 26swg Nichrome
• 32swg Constantin
• 32swg Nichrome
• Stand
• Clamp
• Ruler
• Weights
• Hook

Method

Step 1: Collect all equipment

Step 2: Set-up as diagram below shows.

Step 3: Get a Copper wire, and using a cylindrical object (same size all the time), wrap around to create a spring. The spring needs to be exactly 3cm long. The chosen amount of coils is six, so it has to be six each time.

Step 4: Attach the copper spring to the clamp/stand, making sure it does not unravel or change in shape.

Step 5: Apply 30g of weight to the “hook”.

Step 6: Record the result.

Step 7: Repeat steps 3-6 for each type of wire, once (of each weight), and then change the load.

Step 8: Write up the experiment.

Diagram:

Safety:

Chances of the spring hitting you in the eye are very unlikely, however certain normal precautions – such as standard class rules need to be observed.

Fair Test:

We will try to keep the experiment a fair test. The variables we have chosen are the type of wire, and the amount of load. The amount of coils and size of the wire will be kept the same. We will use the same type of weights, making sure no extra weight (such as small amounts of cello tape) is present. We will take the measurements straight after the movement has stopped, making sure nothing is moving. The experiment will only be done once, which should give us semi-accurate results, but anomalies may ruin this.

Results:

ONE

TWO

THREE

FOUR

FIVE

Graphs:

Analysis  

From the small amount of results I received, it is obvious that the bigger the load, the more the helical spring will stretch, the difference between the stretch and retract will gets bigger as the load increases. This is due to the force acting on the spring gets greater weight causing the gravity on the load to become greater, causing the string to stretch.

Copper stretched more then Nichrome 32, as copper is more malleable, I think the last Nichrome 32 result is an anomaly slightly, as it does not fit the pattern.  

Evaluation

The methods we used seem to be highly effective, and we have got ourselves a set of results that seem to be fairly accurate, and what we expected. We received some anomalous results; this may be due to quick reading of sizes, or lack of time.

Overall I am pleased with the experiment as a whole. A problem that did occur was the making of the springs, as ever so slightly occasionally the spring coil would be bigger or smaller then the others. It would have been fairer to have ready made springs instead.

It would have been helpful to have more time, so we can do the experiment three times, instead of just once, and then do an average, so we receive more accurate results.

Also, the start length of 3cm may not have been true, as we only measured some of the springs, and not all of them, due to a forgetful mistake.

 

The results all seem fairly reliable. The procedure seemed to work impeccably, however we could benefit with more advanced equipment, and better measurement reading techniques. With improvements are experiment could become very accurate and flawlessly conclusive results.