(a)[1]
Define the Young modulus in words.
(b)
Wires P and Q are made from the same material and have the same original length $l_0$. They are secured so that they hang vertically, as shown in Fig. 5.1. The diameter of P is $d$ and the diameter of Q is $2d$. The same force $F$ is applied to the lower end of each wire. Show your working and determine the ratio.
(b(i))[2]
Determine the ratio $\frac{\text{stress in P}}{\text{stress in Q}}$ from the information given.
(b(ii))[2]
Determine the ratio $\frac{\text{strain in P}}{\text{strain in Q}}$ for the two wires.