Answer:

Explanation:
Given that,
Efficiency of heat engine, 
Temperature of hot source, 
We need to find the temperature of cold sink i.e.
. The efficiency of heat engine is given by :




So, the temperature of the cold sink is 256.2°C. Hence, this is the required solution.
A sound wave is a longitudinal wave
Answer: 29.5 days
The waxing moon phase comprises three separate moon phases: the Waxing Crescent, First Quarter, and the Waxing Gibbous.
I believe it’s B; Theories may be proven to be true and become laws.
A would make sense if we were talking about hypotheses however, we’re not.
Answer:
Student 2 protons and valence electrons