What are waves? Wave in physics means an oscillation about a fixed axis or a point that is accompanied by a transfer of energy that travels through the medium like space or mass. Certain waves can travel without a medium too. We will learn about these later. Let’s understand waves with the help of the most common example: water waves.
You have seen innumerable times the effect of dropping a rock into a body of water. This disturbance creates ripples on the surface of the water that seem to move away from the point of disturbance. But if you want to look closer, put a cork in the water. This cork is floating on the surface and now if you drop a rock, this cork will follow the motion of the disturbance created in the water. You will find that the disturbance isn’t really causing any forward or backward motion in the cork; the cork seems content to just move up and down. This is one form of wave travel, another being the subtler changes in the air that transmit sounds etc.
A wave transmits information or energy from one point to another in the form of signals but no material object makes this journey. Frequency of a wave is obtained by including a factor of time in the mix. We are completely dependent on waves for all of our wireless communications.
For example, you make a call to your friend in another city with your mobile phone, the entire communication is happening via audio but the entire process of transmission of signal from the talker to the receiver occurs as a waveform. The phone converts your voice into an electrical signal with then propagates either through copper wires or through antennae in wireless communication.
Types of Waves
- Mechanical Wave: A mechanical wave is a wave that is an oscillation of matter and is responsible for transfer of energy through a medium. The distance of the wave’s propagation is limited by the medium of transmission. In this case, the oscillating material moves about a fixed point and there is very little translational motion. One intriguing property of mechanical wave is the way they are measured, which is given by displacement divided by wavelength. When this dimensionless factor is 1, it results in the generation of harmonic effects; for example, waves break on the beach when this factor exceeds 1, resulting in turbulence.
- Electromagnetic Wave: Electromagnetic waves are created by a fusion of electric and magnetic fields. The light you see, the colors around you are visible because of electromagnetic waves. One interesting property here is that unlike mechanical waves electromagnetic waves do not need a medium to travel. All electromagnetic waves travel through vacuum at the same speed, 299,792,458 ms-1.
- Matter Wave: This concept is a little complicated to understand. The dual nature of matter; its ability to exist both as a particle and a wave was first brought to light by the founders of the field of Quantum Physics. For example, a beam of electrons can be diffracted just like any other bean of electromagnetic radiation or water wave. This property of matter was brought forward by Louis de Broglie’s Hypothesis.
Learn about sound waves, watch this video and the other related videos to visualize concepts of physics like never before:
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