A spring in a door-closing mechanism is 48 mm long when the door is closed. The spring is unstretched when the door is closed. Opening the door increases the length of the spring to 63 mm.
At this length, the spring stores 0.054 J of energy. The spring remains in its linear region.
Calculate the force exerted by the spring when the door is open.
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.