Question

Indicate whether each of the following statements is true or false. 1. The molecules in hot air move at the same speed as in cold air, but there are more molecules so they feel hotter. 2. In a coal-fired power plant, the types of energy from start-to-finish are: electrical, mechanical, thermal, and chemical. 3. In a coal-fired power plant, the approximate percentage of original energy in the coal lost to heat is 10%.

Answer 1

1) False

2) False (chemical, thermal, mechanical and electrical)

3) False

Step-by-step explanation:

1.

We have the expression for the root mean square velocity of the molecules of gases as:

`v_(rms)=\sqrt{(3.k_b.T)/(M) }`

where:

`k_b=` Boltzmann constant

`T=` temperature of the gas

`M=` molecular mass of the gas

2.

In a coal-fired powered the types of energy form start to finish can be given as;

• At first the chemical energy of the coal gets converted into heat energy after the process of combustion.

• Then next, this heat is utilized for generating high pressure steam which drives the turbine converting the heat energy into the mechanical energy.

• Then this rotational motion of turbine shaft is coupled with the armature of the alternator to convert the mechanical energy into electrical energy.

3.

In a coal fired power plant the approximate percentage of original energy in the coal lost to heat is approximately 60%.