A wire that is 1.50 m long at 20.0°C is found to increase in length by 1.90 cm when warmed to 420.0'C. Compute its average coefficient of linear expansion for this temperature range. (b) The wire is stretched just taut (zero tension) at 420.0°C. Find the stress in the wire if it is cooled to 20.0°C without being allowed to contract. Young's modulus for the wire is 2.0 x 1011 Pa.