A student investigated the stretching of a spring by hanging various weights from it and measuring the corresponding extensions. The results are shown in the table below:
Weight / N0246810Extension / mm01631626379\begin{array}{|l|c|c|c|c|c|c|} \hline \text{Weight / N} & 0 & 2 & 4 & 6 & 8 & 10 \\ \hline \text{Extension / mm} & 0 & 16 & 31 & 62 & 63 & 79 \\ \hline \end{array}Weight / NExtension / mm002164316628631079One of the recorded results appears to contain an experimental error. Identify this anomalous result.
Excluding the anomalous result, state and explain whether this spring obeys Hooke's Law.
Describe how the shape of a graph of extension against weight would change if the student continued to add many more weights well beyond 10 N10\text{ N}10 N.
The student estimates that if they hang a 40 N40\text{ N}40 N load on the spring, the extension will be approximately 320 mm320\text{ mm}320 mm. Explain why this estimate may be unrealistic.
245 exam-style questions on CIE IGCSE Physics 1.5 Forces, covering 1.5.1a Forces, resultant force and motion, 1.5.1b Load–extension graphs and the spring constant, 1.5.1c Friction and drag, 1.5.1d Force, mass and acceleration, 1.5.1e Motion in a circular path, 1.5.2a Moment of a force, 1.5.2b Principle of moments and equilibrium, and 1.5.3 Centre of gravity and stability. Each one has a worked solution and a mark scheme showing where the marks go.