Answer:
a --> true, b --> false, c --> true, d -->false
Explanation:
a) since it stays floating the gravity force and the upqards push is the same
b) if it's balanced the rocket won't move from the ground, the force of the rocket, has to exceed the force of gravity
c) since it's going in a diretion the force of gravity is exceeding the force pushing it up
d) since that are speeding up at a rate, meaning growing, the force is unbalanced.
Explanation:
Formula for maximum efficiency of a Carnot refrigerator is as follows.
..... (1)
And, formula for maximum efficiency of Carnot refrigerator is as follows.
...... (2)
Now, equating both equations (1) and (2) as follows.
=

= 
= 
= 2.5
Thus, we can conclude that the ratio of heat extracted by the refrigerator ("cooling load") to the heat delivered to the engine ("heating load") is 2.5.