Tension is 1.3*10^3 N

Sublimation- which change of state is shown in model

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.

Planck decided to assume that atoms could only vibrate at certain frequencies that were whole numbers eg 2f, 3f and so on. others used to think that atoms vibrate continuously

Special care would be an answer