A student investigates the stretching of a spring by hanging weights from it.
The student measures and records the unstretched length l0 l_0\,l0 of the spring (not including the loops at the ends) as 3.2 cm when the load on the spring is F=0.00 NF = 0.00\text{ N}F=0.00 N. Describe one technique that can be used to obtain an accurate value for l0l_0l0.
The student suspends various loads F F\,F from the spring, measures the new length lll, and calculates the extension e=l−l0e = l - l_0e=l−l0. The results are shown in Table 1.1.
Calculate the extension e e\,e of the spring when F=7.50 NF = 7.50\text{ N}F=7.50 N and complete Table 1.1.
Table 1.1
| F/NF / \text{N}F/N | l/cml / \text{cm}l/cm | e/cme / \text{cm}e/cm |
|---|---|---|
| 0.00 | 3.2 | 0.0 |
| 1.50 | 6.8 | 3.6 |
| 3.00 | 10.5 | 7.3 |
| 4.50 | 14.1 | 10.9 |
| 6.00 | 17.6 | 14.4 |
| 7.50 | 21.3 | [ ] |
Plot a graph of F/NF / \text{N}F/N (yyy-axis) against e/cme / \text{cm}e/cm (xxx-axis). Start both axes from the origin (0,0)(0,0)(0,0) and draw a straight line of best fit.
Determine the gradient G G\,G of your graph. Show your working clearly.
The spring constant k k\,k is numerically equal to the gradient GGG. Record the value of k k\,k to a suitable number of significant figures with its unit.
183 exam-style questions on CIE IGCSE Physics 1.5.1a Forces, resultant force and motion. Each one has a worked solution and a mark scheme showing where the marks go.