1. I think a drum would be the easiest instrument to explain. You can vary the pitch and loudness by hitting it with different intensities or at different points or angles.
PS. I'm not talking about a drumset. I'm talking about an ordinary drum.
2. Different types of instruments sound different even though they play the same notes because they use different mechanisms for producing sound.
Entropy is the measure of the amount of disordered in a system.
<u>Explanation:</u>
In 1850, Entropy introduction by the German physicist Rudolf Clausius refers a measurement of the system's thermal energy in unit temperature. It is not for useful work because the work originates from ordered molecular motions. And, this also measures the molecular disturbance or randomness of the system.
The concept behind this provides deep view into spontaneous changes in many everyday phenomena’s. The idea of entropy is a mathematical way of coding an intuitive idea whose processes are impossible, and not violate the basic principle of energy conservation.
Radiation: Getting sunburnt on a beach.
- The sun’s radiation (no direct contact) is what causes the skin to burn.
Radiation: Microwave cooking food
- Microwaves use radiation to heat the food inside of it; between radio waves and infrared radiation on the electromagnetic spectrum
Conduction: Touching a hot car seat in the summer
- Conduction is the transfer of heat by direct contact (hand to seat).
Conduction: Burning yourself with a curling iron (Similar to above; direct contact).
Convection: An ocean breeze
- Convection near coastlines cause the transfer of energy; water warms and cools slower than land.
Conduction: Sliding down a hot metal slide in august
- You are in direct contact with the slide, which is hot due to the temperature.
Convection: Water in a boiling pot of macaroni
- The water, a liquid, is being heated by molecular motion.
Convection: Currents deep within the earth that cause tectonic plates to move
- Convection currents drive the movement of tectonic plates in the mantle, which is fluid/molten. The currents circulate under the asthenosphere.
Answer:
We have to show surface area 
,with few conditions that is by considering Force 
and Pressure 
to be respectively.
Explanation:
The atmospheric pressure is 
on Earth's surface.
The magnitude of the force exerted on a person by the atmosphere is 
.
Now to calculate surface area we can find it from 
and re-arranging it to.
So plugging the values,
Surface area 
Hence from the above calculations we can say that surface area is 
.
So the surface area of an average person can be said to have , using the concept of pressure and force.
