An engineer is choosing a spring for the emergency stop on a moving inspection carriage.
The spring must:
The engineer tests three springs, L, M and N. The extension produced by 3000 N is within the linear region for each spring.
The final column gives the extension remaining after each spring has been stretched by a force of 12 000 N12\,000\ \text{N}12000 N and then unloaded.
| Spring | Extension at 3000 N in mm\text{mm}mm | Force at the limit of proportionality in N\text{N}N | Extension remaining after unloading in mm\text{mm}mm |
|---|---|---|---|
| L | 45 | 12 00012\,00012000 | 0 |
| M | 36 | 14 00014\,00014000 | 0 |
| N | 50 | 10 00010\,00010000 | 12 |
Evaluate which spring is the most suitable for the emergency stop.
Use calculations in your answer.
Use the equation
E=12×k×x2\displaystyle E = \frac{1}{2} \times k \times x^{2}E=21×k×x2
102 exam-style questions on Edexcel GCSE Physics 15.1 Forces and springs, covering 15.1.1 Elastic and inelastic distortion, 15.1.2 The spring constant, 15.1.3 Work done in stretching a spring, and 15.1.4 Linear and non-linear force–extension. Each one has a worked solution and a mark scheme showing where the marks go.