Answer:
As a type of thermal power station, a coal-fired power station converts chemical energy stored in coal successively into thermal energy, mechanical energy and, finally, electrical energy. The coal is usually pulverized and then burned in a pulverized coal-fired boiler.Coal-fired plants produce electricity by burning coal in a boiler to produce steam. The steam produced, under tremendous pressure, flows into a turbine, which spins a generator to create electricity.
Answer:

Explanation:
Given data
Length of tube L=0.632 m
Speed of sound v=344 m/s
To find
Fundamental frequency f
Solution
The fundamental frequency of the tube can be given as:

The mechanical efficiency = actual work / ideal work
So ζ = 1540 / 1600 * 100% = 96.25%
Answer:
C) 40 N/m
Explanation:
If we ASSUME that the spring is un-stretched at the zero cm position
k = F/Δx = 10/0.25 = 40 N/m
11.86 years. Usually memorized as "12 years".