A toy launcher uses a spring to fire a small ball.
The spring has a spring constant of 200 N/m. The spring is compressed by 0.050 m.
Calculate the energy stored in the compressed spring.
Use the equation
E=12×k×x2\displaystyle E = \frac{1}{2} \times k \times x^{2}E=21×k×x2
Calculate the force needed to hold the spring compressed by 0.050 m.
The spring is now compressed by 0.10 m. A student says:
'The energy stored in the spring will be twice as big.'
Explain why the student is wrong.
To compress the spring, the ball pushes on one end of the spring and the base of the launcher pushes on the other end.
Explain why both of these forces are needed to compress the spring.
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.