Answer:
It is called an electronic signal.
Answer:
a

b

Explanation:
From the question we are told that
The wavelength is 
The energy is 
This energy is mathematically represented as

Where c is the speed of light with a value 
h is the Planck's constant with the value 
n is the number of pulses
So

substituting values


Given that the pulses where emitted 20 times in one second then the period of the pulse is


Hence the average power of photons in one 80-mJ pulse during 1 s is mathematically represented as

substituting values


- It helps in regulating extremes in the environment.
- It can be used as a car radiators.
<u>Explanation:</u>
- The amount of heat needed to raise a certain amount of temperature to the water is known as the specific heat of the water. For one gram of water to increase 1 degree celsius, water needs to absorb 4.184 J of heat.
Some of the uses of high specific heat of water are as follows,
- The temperature of the water will remain the same from day to night in ponds or sea. During day time, the hot air from the sea or pond rises while the cool air from the sea moves to take its place. During the night, the hot air from the land moves to take its place, giving rise to a land breeze and thus maintaining the environment.
- Another example, When water is circulated throughout an engine, heat will get absorbed. This water is pumped to a radiator and then disposed to the surrounding air.
Answer:
If you have two batteries and they have precisely the same voltage then placing one backwards will effectively cancel out the voltages and no current will flow. However, batteries aren't like that. The slightest difference in voltages mean that current will flow.
Explanation: