(a(i))[1]
In the deformation of a wire under tension, state what stress means.
(a(ii))[1]
In the deformation of a wire under tension, state what strain means.
(b(i))[3]
Describe a method for taking measurements so that the cross-sectional area of the wire is found accurately.
(b(ii))[2]
Determine the Young modulus $E$ for the material of the wire.
(b(iii))[2]
Use Fig. 3.1 to calculate how much the energy stored in the wire increases when the load rises from $2.0\,\text{N}$ to $4.0\,\text{N}$.
(c)[2]
In (b), the wire is changed to a new one made of the same material. The replacement wire has twice the length and twice the diameter of the original wire. It also follows Hooke’s law. On Fig. 3.1, sketch how the load $F$ varies with extension $x$ for the new wire from $x = 0$ to $x = 0.80\,\text{mm}$.