Physics 207 - Lab m 10

Welcome to lab M 10 Young’s modulus of elasticity and hooke’s law The objective of the lab is to study the elastic properties of piano wire under tension. You will be using 1 kilogram slotted weights Frame and support stand for holding steel wire. Micrometer to measure elongation. Each division on the micrometer is equal 0.01 millimeter . Young’s modulus My is the ratio of longitudinal stress to the resultant longitudinal strain: My = stress/strain On rearranging the terms it can be seen that this is equivalent to hooke’s law with the spring constant in this case equal to MyA/L Place three kilograms to straighten the wire. The wire is stretched by two equal forces from both the sides. You have to measure the length of the wire under stress, which is not the complete length of the wire. Start by adding weights to the hanger and simultaneously note down the elongation produced by measuring the successive counter deflections. One complete rotation of the counter needle means the elongation is 1mm. Repeat the same process by fully loading the hanger and then removing the weights one by one. You can then generate a plot using excel and get the desired value of young’s modulus.