What is the wavelength of the sound you hear as a train blowing its whistle is coming towards you?
a
The wavelength is shorter than the sound of the
whistle at rest
b You will not hear anything
С
There is not enough information to answer this
question
d
The wavelength is longer than the sound of the
whistle at rest
e
The wavelength is the same as the sound of the
whistle at rest

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.