(a)[1]
State the Young modulus of a material.
(b(i))[1]
State an expression, in terms of some or all of $L$, $A$, $E$ and $\rho$, for the resistance $R_0$ of the wire.
(b(ii))[2]
Show that the spring constant $k_0$ of the wire can be written as $k_0 = \dfrac{EA}{L}$.
(c(i))[1]
On Fig. 3.1, sketch the way in which the resistance $R$ of the wire varies with $F$.
(c(ii))[1]
On Fig. 3.2, sketch how the spring constant $k$ of the wire varies with $F$.
(d(i))[1]
Copper has a resistivity of $1.8 \times 10^{-8}\,\Omega\,\text{m}$ and a Young modulus of $1.3 \times 10^{11}\,\text{Pa}$. A copper wire with diameter $1.6\,\text{mm}$ has a resistance of $0.034\,\Omega$. Show that the wire length is $3.8\,\text{m}$.
(d(ii))[2]
Use the equation from part (b)(ii) to find the spring constant of the wire.