4. Discussion

4. Discussion

4.1 Key findings & Analysis of results

From the graph, it can be seen that as more springs are added in series, the effective elastic constant of the springs dropped while adding more springs in parallel would increase its effective elastic constant. For example, one spring’s average elastic constant is 13.1N/m, but when adding another spring to it in series, its average effective elastic constant dropped to 6.6N/m which is about half of its original. likewise for parallel. When putting 2 springs in parallel, its average effective elastic constant increased to 25N/m which is almost double of the original spring’s elastic constant. However, we noticed that when adding two springs in series and parallel as shown in set-up 6 of figure 2.2.1, its effective elastic constant is the same as one spring on its own. 

4.2 Explanation of key findings  

From this experiment, it can be seen that adding two springs in parallel doubled its effective elastic constant and adding 2 in series halved its effective elastic constant. This led us to a conclusion that the elastic constant of a combination of springs in parallel is( keq = k1+k2) with k1 and k2 being the original springs elastic constant and keq being the effective elastic constant. Likewise for series, we came to the conclusion that the formula for the effective elastic constant is (1/keq = 1/k1+1/k2) (Stefan.v, 2016). This is because when you exert a force on 2 springs arranged in series, the same force will be exerted on 2 springs and thus doubling the extension of it, which causes its effective elastic constant to decrease. And when you exert a force on 2 springs arranged in parallel, the force is evenly distributed among both springs, thus halving its extension which causes its effective elastic constant to increase. This is why combination 1(one spring) and 6 (2 springs in series and parallel) had the same elastic constant.(Ken Dobson, 2002). 

4.3 Evaluation of Hypothesis

Comparing this result back to our hypothesis, it has been shown the hypothesis, as more springs are added in series, the effective elastic constant would decrease, and, as more springs are added in parallel, the effective elastic constant would increase has proven to be true. As the number of springs added in series increased, the springs’ effective elastic constant decreased and as the number of springs added in parallel increased, the springs’ effective elastic constant increased. This shows that the hypothesis is correct.

4.4 Limitations and Areas for improvement 

When doing the experiment, we could have improved our way of measurement. We had a ruler that had a rounded end and had to hold the ruler above the ground and leave it to dangle, which may have made our readings inaccurate due to human and parallax errors. We could improve on this by having a proper metre rule with a flat top and reading the measurement from eye level. Another thing that did not allow us to carry out the experiment properly was the fact that we did not know which part of the spring to measure as when the spring stretched, it was difficult to see the end of the spring and sometimes we could not read the ruler properly. We can use a pointer next time at a specific part of the spring so that the pointer will point to the ruler, allowing for easier and more accurate readings. One more thing that could be improved was the balancing of weights. Sometimes when doing springs in parallel, it was difficult to balance the weight in between the springs especially when we were using heavier weights, a little movement could cause the weight to slide to one side and cause the whole set-up to fall down. We can improve this by finding the exact centre of the chopstick and mark it by adding a dent so that the weight can be put nicely into the centre. The springs on the other sides would also have to be of the same distance apart.