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%.

1) False

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

3) False

Explanation:

1.

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

where:

Boltzmann constant

temperature of the gas

molecular mass of the gas

2.

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

3.

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

half of a circle

explanation:

the arrow and the top of the circle is matching together. it is not a polygon because a polygon would always be the same shape. therefore, an half of a circle is called semicircle so you would find the radius of it.