Simple
harmonic motion is a motion that repeats at a constant tempo, (Italian
for "time", Tempo
is the speed of a given piece.) Take
a pendulum. As it swings back and forth it is always
a constant rate.
Depending on the string length the tempo may become different.
For example if the string is short, it has a faster tempo but if
the
string is longer the tempo is longer.
Simple harmonic motion was discovered by Galileo
when he was attending mass. He noticed a lamp swinging back
and
forth
with no help.
He also noticed that the lamp didn't slow down as it swung back
and forth. It kept the same tempo even as the amplitude or height of
the swings decreased over time. He was on the verge of making a great
discovery. He timed this motion with his own pulse. The discovery he
made was important for many reasons.
Keeping accurate time
was not possible before Galileo's discovery, but this discovery
is how clocks came to be. A good example of how clocks use simple
harmonic motion is the grandfather clock. The grandfather clock
is a very tall clock woth a pendulum attached to the gears of the
clock. With every swing the clock advances forward one second.
If a weight is not placed on the pedulum the grandfather clock's
swings will get smaller and smaller. This will eventually cause
it to stop.
Harmonic
motion can also be described with a spring with a weight at the end.
When
the spring moves up and down, at a constant tempo,
simple
harmonic
motion is taking place. The tempo of the spring depends on the strength
and
thickness of the spring. The formula that is used to express the
force of the spring is F=-kx.
There is harmonic motion located everywhere in the world.
It is waves from the ocean sound waves, light waves, molecules in crystals
and electronics. It is everywhere. Harmonic
motion
makes
up some of the most fascinating things in this world. Look around you
can you tell of anything that moves in harmonic motion?
