how light is important to us?? please write 5 points
Answers
Answer:
Light Is a Wave
What is a wave? Let's start with an example. Toss a rock into a puddle and you will see something like this:
SLOW MOTION VIDEO OF WAVES IN A PUDDLE.
The rock makes a disturbance in the water (a ripple). This disturbance moves radially outward from where the rock hit. It is the disturbance moving outward, not the water molecules - they just move up and down. You can do something similar with a length of string. Place it on the floor and continue to shake one end. The disturbance travels down the string (a heavy string works better).
Let's look at the case of a wave traveling down a string. There are 4 properties that you could consider:
These 4 properties are:
Amplitude: this is the size of the displacement for the disturbance. The units for amplitude depend on the type of wave. For a string, the units would be meters.
Wave speed: if you were to watch one displacement, it would be moving. The wave speed is the speed (that seems redundant). The unit for wave speed is meters per second.
Wavelength: this is the distance from one disturbance to the next measured in meters
Frequency: if you were to count how many waves passed a stationary point in each second, that would be the frequency (in cycles per second or Hertz).
The last three properties are related. The speed of the wave is equal to the product of the wavelength and the frequency.
So, light is a wave. This means that it has all the above properties and can do wavey things such as:
Expand and radiate in all directions (like a lightbulb or the waves in the water caused by a rock).
Interfere with other waves.
Bend around corners (yes, light does this - but it's difficult to see).
Carry energy and momentum.
Interact with matter.
Answer: