Freddy (50 kg) is sitting on a tree branch 10 m above the ground. He then climbs to a higher branch 15 m above the ground. How much work has Freddy done climbing from the first branch to the second?

The best description is: . nobody has any idea what q is.

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.