A block with a mass of 6.0 kg is held in equilibrium on an incline
of angle θ = 30.0° by a horizontal
force, F, as shown in the figure.
Find the magnitudes of the
normal force on the block and of F. (Ignore friction.)

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.

Motion i think. hope it

D. a  bar magnet with its south pole on the left