An automatic gate uses two identical return springs. During normal operation, the springs are in their linear elastic region. Each spring has a spring constant of 4500 N/m.
A total force of 360 N is shared equally between the two springs as the gate opens.
Calculate the extension of each spring.
At another position, each spring has an extension of 0.020 m.
Calculate the elastic potential energy stored in each spring.
Use the equation
E=12×k×x2\displaystyle E=\frac{1}{2}\times k\times x^2E=21×k×x2
A flexible strip on the edge of the gate bends if the gate touches an obstacle. The strip must return to its original shape so that it can be used again.
Two materials are tested using the same bending force.
| material | displacement of the end while the force is applied in mm | displacement of the end after the force is removed in mm |
|---|---|---|
| P | 18 | 0 |
| Q | 14 | 4 |
Suggest which material should be used for the flexible strip and why.
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.