A metal wire is subjected to a known tensile force. The wire remains below its limit of proportionality. Which two measurements are needed to calculate the strain in the wire?
- Athe unstretched length of the wire and the cross-sectional area of the wire
- Bthe unstretched length of the wire and the extension of the wire
- Cthe Young modulus of the metal and the extension of the wire
- Dthe Young modulus of the metal and the unstretched length of the wire