A student hangs various masses from the end of a spring and determines the extension produced. Fig. 2.1 shows the spring hanging vertically on its own and with an unknown mass X at one end. [Figure 2.1 (not to scale)] (a) The student plots a graph of the extension of the spring against the mass hanging on the spring. Fig. 2.2 shows the student's graph. [Figure 2.2]

1. (a)(i)At point P on the graph, the line begins to curve. State the name of point P.[1]
2. (a)(ii)Using Fig. 2.1 and Fig. 2.2, determine the mass X.[1]
3. (a)(iii)The gravitational field strength g is 10N/kg. Calculate the weight of X.[1]
4. (b)An identical spring is used with the original spring, as shown in Fig. 2.3. Together they support the mass X. [Figure 2.3 (not to scale)] State and explain how the extension in Fig. 2.3 compares with the extension in Fig. 2.1.[2]

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.