Quick answer: Hooke's law says extension is proportional to force (F = kx) up to the limit of proportionality. This Physics 11-12 test on Young modulus has 8 questions worth 20 marks, to do in 45 minutes: stress and strain, spring energy and reading a stress–strain graph. The mark scheme is on a separate page; free printable PDF.
This test lasts 45 minutes and is worth 20 marks. Use g = 9.81 N/kg, show every step of your working, give answers with units and convert all lengths to metres before substituting.
Level: Physics grades 11-12 (A Level · IB · Class 11-12) · Curriculum: A Level 3.4.2
Question 1 Stress and strain (3 marks)
A steel wire of diameter 1.2 mm carries a load of 90 N (E = 2.0 × 10¹¹ Pa).- Calculate the cross-sectional area. (1 mark)
- Calculate the stress. (1 mark)
- Calculate the strain. (1 mark)
Question 2 Spring energy (3 marks)
A force of 25 N extends a spring by 0.080 m.- Calculate the force constant. (1 mark)
- Calculate the energy stored. (2 marks)
Question 3 Reading a stress–strain graph (3 marks)
The graph is for a metal wire.- Calculate the Young modulus from the straight part. (2 marks)
- Name the quantity represented by the stress at X. (1 mark)
Question 4 Aluminium wire (3 marks)
An aluminium wire (E = 7.0 × 10¹⁰ Pa) is 3.00 m long with diameter 1.0 mm. A 40 N load is attached.- Calculate the stress. (1 mark)
- Calculate the strain. (1 mark)
- Calculate the extension in mm. (1 mark)
Question 5 Elastic and plastic (2 marks)
A wire is stretched beyond its elastic limit and then the load is removed. Explain what happens to its length and why.Question 6 Brittle fracture (2 marks)
Explain the shape of the stress–strain graph of glass and why glass is described as brittle.Question 7 Extra energy (2 marks)
A spring of force constant 400 N/m is stretched from an extension of 0.020 m to 0.050 m. Calculate the extra energy stored.Question 8 Area under a graph (2 marks)
State what the area under a force–extension graph represents and explain why it is not always recoverable.
