In this experiment you will investigate the stretching of a spring. You are provided with: • two bosses, clamps and stands • a steel spring • a set square • a metre rule with a millimetre scale • a set of 1.0 N loads. The spring and the metre rule have been set up for you as shown in Fig. 3.1. Do not remove the spring from the clamp or adjust the height of the clamp. [Figure 3.1]

1. (a)(i)Take the reading R₀ on the metre rule level with the top of the spring. Take the reading R₁ on the metre rule level with the bottom of the spring. Do not include the loops at the top and the bottom of the spring in your measurements. Use the set square to help you take the readings. Record your readings to the nearest 0.1 cm. reading R₀ = ................................... cm reading R₁ = ................................... cm [2][2]
2. (a)(ii)Draw on Fig. 3.1 to show how you use the set square to take a reading from the metre rule level with the bottom of the spring. [1][1]
3. (a)(iii)Calculate the length l of the spring with no load suspended from it. Use the equation shown: l = R₁ – R₀ Show your working. Record R₀ and l in Table 3.1 for load L = 0.0 N. [1][1]
4. (b)(i)Place a load L = 1.0N on the spring. Take readings to determine the new length l of the spring. Record the new reading R₁ and the new length l of the spring for load L = 1.0N in Table 3.1. [1][1]
5. (b)(ii)Repeat the procedure in (b)(i) for loads L = 2.0N, 3.0N, 4.0N and 5.0N, and record your values of R₁ and l in Table 3.1. You may use the space provided for working. [1][1]
6. (c)On the grid provided in Fig. 3.2 on page 11, plot a graph of l on the y-axis against L on the x-axis. Start from the origin (0, 0). Draw the straight line of best fit. [4][4]
7. (d)Use your data in Table 3.1 and the graph in Fig. 3.2 to determine the extension of the spring when a load of 3.5N is added to the spring. Show your working. extension = ................................... cm [2][2]
8. (e)A student suggests that the stretched length l of the spring is directly proportional to load L. State if your data supports this suggestion. Justify your statement using your data in Table 3.1 on page 10 or the graph in Fig. 3.2 on page 11. statement justification [1][1]
9. (f)Line of sight (parallax) errors can occur when readings are taken from a metre rule. State one practical technique, other than using a set square, that ensures accurate readings are taken from a metre rule. [1][1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.