Ductility of material with work hardening

What is the speed of sound in Neon gas at a temperature of $$500$$ $$K$$ (Gas constant of Neon is $$0.4210$$ $$kJ/kg$$-$$K$$)?

A Carnot cycle is having an efficiency of $$0.75.$$ If the temperature of the high temperature reservoir is $${727^ \circ }C,$$ what is the temperature of low temperature reservoir?

The efficiency of superheat Rankine cycle is higher than that of simple Rankine cycle because