Two plane mirrors are placed 75 cm apart with their mirrored surfaces parallel and facing each other. If the mirrors are 10 cm wide, at what angle should a beam of light be incident at one end of one mirror so that it just strikes the far end of the other?

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.

Cardiac muscle causes movement in the bone.

The inference is supported by evidence in the graph is this is an exothermic reaction where the total release of energy equals a + c.