Physics Course/Periodic Motion

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Periodic Motion[edit]

Periodic motion refers to any motion moving at a distance above and below the equilibrium position and this motion keeps repeat itself over a period of time. This type of motion is also called Oscillation .

Examples[edit]

  1. The moving up and down of a spring
  2. The swinging side by side of a pendulum

Analysis[edit]

The moving up and down of a spring[edit]

When apply a force on an object of mass m attach to a spring , the spring will move a distance y above and below the equilibrium point

The force acts on the object is

F = m a

The Restoring Force of spring is given by Hook's law as

Fs = - k y

When The Net Force on the system is 0 then there is no movement

F - Fs = 0
m a = - k y
y = \frac{m a}{k}
a = - \frac{k}{m} y
v t = \frac{k}{m} y
t = \frac{k}{m} \frac{y}{v}

The swinging side by side of a pendulum[edit]