A student records the force and extension of a spring that obeys Hooke's law. The student correctly converts extension from centimetres to metres when finding kkk. When using E=12kx2\displaystyle E=\frac{1}{2}kx^2E=21kx2, the student uses the numerical extension in centimetres. How does the calculated energy compare with the correct energy?
It is 100001000010000 times as small.
It is 100100100 times as large.
It is 100001000010000 times as large.
It is 100100100 times as small.
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.