Simple Harmonic Oscillations Flashcards
Define displacement.
The distance from the equilibrium point.
Describe an example of a free oscillation.
If an oscillating spring transfers no energy to its surroundings, it will keep oscillating at with the same amplitude forever. This is called a free vibration (even when not perfect).
Define amplitude.
The maximum displacement from the point of equilibrium.
Define period.
The time taken for one complete oscillation.
Define frequency.
The number of oscillations per second.
Define angular frequency.
Radians per second.
Define phase difference.
How far a point on a wave is leading ahead or lagging behind a point on another wave.
Define simple harmonic motion.
An oscillation of which the acceleration is directly proportion to it’s displacement from the equilibrium position, and is always directed towards the equilibrium position.
How is the period of an oscillating body related to it’s amplitude?
They are not related, the are independent of one another.
Describe the changes in displacement, velocity and acceleration in SHM.
When amplitude is at its greatest, velocity is zero, and amplitude is at its minimum. When velocity it at its greatest, both displacement and acceleration are 0. When acceleration is at its greatest, displacement is at its minimum, and velocity is zero.
Describe and explain the interchange between kinetic and potential energy during simple harmonic motion.
The sum of PE and KE is always constant. KE is greatest at equilibrium position, and PE is greatest at maximum amplitude. The energy change happens gradually. The change happens because as the objects is moving back towards the equilibrium position, work is done to convert the energy to KE.
Describe the effects of damping on an oscillatory system.
Damping reduces the amplitude of the oscillation over time. The heavier the damping, the quicker the amplitude reaches zero. It happens because the systems absorb energy.
Describe a practical examples of forced oscillations and resonance.
If a speaker is positioned next to a glass, the glass will smash if the amplitude becomes too great. This happens if the frequency of huge speaker matches the natural frequency of the glass. This causes resonance.
Describe how the driving frequency-amplitude graph changed when the driving frequency approaches the natural frequency.
The graph rises with an increasing gradient until the natural frequency is reached, where there will be a sharp peak. The amplitude will then lower with decreasing gradient as the driving frequency passes the natural frequency.
Give an example of where resonance is useful.
Musical instruments, microwave ovens, MRI scanning.
