(a)[1]
What is the definition of strain?
(b(i))[2]
A wire is intended so that its strain stays below $4.0 \times 10^{-4}$ when a force of $8.0\,\text{kN}$ acts on it. The Young modulus of the metal in the wire is $2.1 \times 10^{11}\,\text{Pa}$. You may assume Hooke’s law applies. For a force of $8.0\,\text{kN}$, calculate the maximum stress for the wire.
(b(ii))[2]
For a force of $8.0\,\text{kN}$, calculate the minimum cross-sectional area of the wire.
(b)
A wire is intended so that its strain stays below $4.0 \times 10^{-4}$ when a force of $8.0\,\text{kN}$ acts on it. The Young modulus of the metal in the wire is $2.1 \times 10^{11}\,\text{Pa}$. You may assume Hooke’s law applies. For a force of $8.0\,\text{kN}$, calculate, for the wire: