High School Physics

# What is a wave and how it helps in energy transfer? Explain with graphs

Last updated on April 14th, 2021 at 01:44 pm

What is a wave? A wave is a means to transfer energy from one place to another via oscillations without causing any net movement of any matter.

## Mechanical Wave

A mechanical wave is a wave that needs some sort of mechanical medium or substance that oscillates to allow the transfer of the energy. The sound wave of a human voice is an example of a mechanical wave. This sound wave of a human voice transfers energy from one person’s vocal cords to another person’s eardrum by the repeated vibrations of the air molecules.

## Electromagnetic waves

On the other hand, Electromagnetic waves can transfer energy with the help of repeated oscillations of electric and magnetic fields. But in this case, these fields don’t require any matter to support them. In fact, the interference caused by the presence of any matter generally slows this kind of energy transfer. For example, light travels with a slower speed in water compared to its speed in a vacuum.

## Understanding Waves with Graph | Graphing waves

Let’s graph the displacement of a particular point in the wave (along the y-axis) versus the distance traveled by the wave (along the x-axis). – figure 1

Now let’s graph the displacement of a particular point in the wave with respect to time. (figure 2)

Note: Displacement here denotes the position of a particular point on the wave, at a particular instant in time, measured from the mean (equilibrium) position