Apparatus: The wire is secured by a clamp and clamp stand A hanging mass is attached to the end of it, where the mass hung can be changed A Vernier scale or ruler may be attached to the apparatus to measure the distance the wire has extended Measurements: The initial length of the wire can be measured using a ruler (or metre rule) The wire diameter can be measured with a micrometer The mass attached can be measured using weighing scales (or by using known masses) The extension can be measured using a Vernier scale (or ruler) for a range of different masses Calculating Young’s Modulus: E= stress/strain So E is the gradient of a stress-strain graphStress=F/A=mg/πr2 Strain= extension/initial length Readings for extension can therefore be taken for different masses. The stress and strain can be calculated and plotted on a graph, and E can be measured from its gradient.