(a) 0.249 (24.9 %)
The maximum efficiency of a heat engine is given by

where
Tc is the low-temperature reservoir
Th is the high-temperature reservoir
For the engine in this problem,


Therefore the maximum efficiency is

(b-c) 0.221 (22.1 %)
The second steam engine operates using the exhaust of the first. So we have:
is the high-temperature reservoir
is the low-temperature reservoir
If we apply again the formula of the efficiency

The maximum efficiency of the second engine is

Pulling a dogs leash: inertia
B is the answer, I’m really good at this subject
Answer: Atoms are electrically neutral because they have equal numbers of protons (positively charged) and electrons (negatively charged). If an atom gains or loses one or more electrons, it becomes an ion.