A technician tests a spring used in a self-closing gate. The spring obeys Hooke's law over the range tested.
The technician records the force and the total length of the spring at two different non-zero forces. The technician calculates the spring constant by dividing the change in force by the change in total length.
Which describes the result of the technician's calculation?
A value that is too small, because each total length is greater than the corresponding extension
No valid value for the spring constant, because neither reading was taken with zero force
The correct spring constant, because the change in total length equals the change in extension
A value that is too large, because the original length has not been subtracted from either reading
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.