Suppose a heat engine is connected to two energy reservoirs, one a pool of molten aluminum at 660°c and the other a block ofsolid mercury at -38.9°c. the engine runs by freezing 3.00 g ofaluminum and melting 45.0 g of mercury during each cycle. thelatent heat of fusion of aluminum is 3.97 105 j/kg, and thatof mercury is 1.18 104 j/kg.
(a) what is the efficiency of this engine?
%
(b) how does the efficiency compare with that of a carnotengine?
%

a)

b)

Explanation:

Given:

a)

Heat absorbed by the engine:

Heat rejected by the engine:

Now the efficiency of the engine:

b)

Now the Carnot efficiency of the engine:

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards