Waves are movements of energy
Waves are a topic of particular interest in physics because many
natural phenomena – light, sound, and yes, water waves - occur
as waves.
Th ink about waves you seen on the water.
What do you know about waves?
In physics, a wave is a disturbance which moves through a medium
(water, air, a slinky) from one point to another. The key point is that
it is the disturbance that moves, not the medium. The disturbance
is caused by energy transferring from one particle to another, so
waves are sometimes called energy transfer phenomenon.
Have you ever been in a boat?
What happens to the boat when the water is wavy?
Waves of energy can pass back and forth
through the metal coils of a Slinky while
the Slinky as a whole never moves.
Tsunami 3
Amplitude and energy: Why size matters
What happens to waves in a really strong wind or hurricane?
Every wave can be described by its amplitude, wavelength and period.
So, as devastating as tsunamis are for both people and property,
their formation and actions are governed by physics.
The amount of energy carried by a wave is related to its amplitude.
High energy waves have large amplitudes and low energy waves
have smaller amplitudes. In other words, bigger waves have way
more energy than smaller waves – and tsunamis are BIG waves.
The energy (E) in a wave is actually proportional (α) to the square
of its amplitude (A).
E α A2
This means that every time the amplitude of a wave doubles, the
energy it contains actually increases 4 times.
So while an every day 1m wave has 1 unit, a large tsunami of 32m
has over 1000 times more energy. The largest tsunamis are about
30 meters high when they hit land.
Waves on water are usually caused by the wind. Individual molecules
of air traveling over the water’s surface crash into individual
molecules of water, and in doing so transfer energy to them. The
water particles then transfer energy to other nearby particles of
water and so on. We see this energy transfer as a ripple on the water,
or in heavier winds (which transfer more energy), waves. This
process keeps on going from one set of molecules to the next until
the waves reaches the shore.
All waves are energy transfer
phenomena.
Posted by Aneka Tips
on 17.01. Filed under