1. A copper wire has length 200cm and radius 0.40mm. A mass of 1.00kg is suspended from the end and allowed to come to rest. The Young modulus of copper is 130Pa. Calculate: a) the stress b) the strain c) the extension d) the elastic energy stored Repeat the calculations for the case of a carbon fibre of Young modulus 7500GPa. 2. stress=F/A strain=deltax/L E=stress/strain let gravity=-10m/s let deltax = ^x 3. a) F = 1.0kg x 10m/s = 10N Stress = 10/π0.00042=25000Pa, 25kPa b) Now I'm already stuck because I don't have ^x to calculate the strain.