Waves - Introduction
Waves - Transfer energy from one place to another, but doesn't transfer matter.
How do waves transfer energy?
Waves transfer energy through vibration or oscillation. When a body vibrates or oscillates, the energy is being transferred, however the matter is returning to it's resting place. why?
It is because of it's restoring force. The restoring force, for example in a pendulum, is gravity. The restoring force is opposite to the direction of the displacement, therefore the object come to it's resting point. But because of the inertia, the object continues to moves, however in the opposite direction, as the restoring force changed the direction of the object's displacement. the cycle repeats. But due to friction, the cycle will not last forever.
What is the difference between Oscillation and Vibration?
Vibration is a type of oscillation, but in this circumstances, vibration is considered the movements with low amplitude and high frequency, and oscillation with high amplitude and low frequency.
Describing an Oscillation
Oscillation is the movement of a body from its resting place to the maximum distance it can cover on one side to the maximum distance on the other side and back to its resting place.
all movements ≠ all oscillation
all back and forth movements ≠ all oscillation
all oscillation ≠ all vibration
The maximum distance that the body covers on either side of its resting place is equal from its resting place and is called the amplitude or maximum displacement. The resting point of the body is known as its equilibrium state. Oscillation has a definite time period which means the body takes a definite time to complete one oscillation and will remain same for all oscillations if there is no outer force working on the system. It is known as periodic movement.