Answer:
Best example would be Carnot engine. It is possible in theory not in real life.
Explanation:
In real engines, the heat transfers at a sudden change in temperature whereas in a Carnot engine, the temperature remains constant. In our day to day lives, reversible processes can't be carried out and there is no such engine with 100 % efficiency. Thus, the Carnot cycle is practically not possible.
The troposphere is mostly heated by the transfer of energy from the surface. <span />
Answer:
D. Both A and C
Explanation:
I'm guessing D. states 'Both A and C', since it works.
Process:
A. sin 18° = 0.31, and cos 72° = 0.31
A. works!
B. sin 55° = 0.82, and cos 55° = 0.57
B. does not work!
C. sin 72° = 0.95, and cos 18° = 0.95
C. works!
Hope this helps!
Options A and D are true. The other two options are absurd and not even based on fact while A & D are true concerning this part of Africa at that time.
