Elastic strain energyEdexcel A-Level Physics: Mind map

Exam questions on Elastic strain energy

1. A spring of stiffness 250 N m⁻¹ obeys Hooke's law. It is extended by 0.060 m.
   The spring is attached to a trolley of mass 0.30 kg on a frictionless horizontal track. When released from this extension, all of the stored energy becomes kinetic energy of the trolley. Calculate the maximum speed of the trolley.2 marks
2. A metal wire obeys Hooke's law up to a force of 40 N, at which its extension is 2.0 mm.
   A student calculates the work done in stretching the wire to 40 N as 40 N × 2.0 mm = 0.080 J. Explain why this is incorrect and give the correct value.2 marks
3. A strip of elastic polymer is stretched within its elastic limit, and the force is measured at 2.0 mm intervals of extension. The readings are: 0 N at 0 mm, 3.0 N at 2.0 mm, 5.0 N at 4.0 mm, 6.0 N at 6.0 mm and 6.5 N at 8.0 mm. The graph of force against extension is a curve whose gradient decreases as the extension increases.
   Estimate the elastic energy stored in the strip when its extension is 4.0 mm.3 marks