<span>It is light, easily shaped, strong, and inexpensive. Its ability to guard against contamination makes it useful in sterile medical environments such as hospitals.</span>
Answer
Gravitational force is between two object caused by energy in mass. Here when you are in a mine the radius of the earth in case of calculating gravity is reduced to the length between you and the center.
This means the mass of earth is decreasing even though the distance is decreasing. Relative to the decrease in distance squared the decrease in the mass of the second object(earth) is more. As a result your weight decreases.
The altitude is usually low. Tropical places are mainly on the ocean, that's usually why it's so hot. They are usually close to the equator, but not right on it. The tropics get a lot of direct sunlight, so wear that sunscreen! The ocean currents are warm, so they bring along warm water. All of those help make the tropics the way they are.
Hope this helps
To develop this problem we require the concepts related to wavelength and its expression to calculate it.
The wavelength is given by

Where,
light velocity
f = frequency.
Our values are given by,



Then,
Visible
Gamma Ray
Infrared
<em>*Note the designation on the type of rays that are, can be found in consulted via On-line or in the optical books referring to the electromagnetic spectrum table with their respective ranges.</em>
The Quantum Theory
Hope this helps