Simple Harmonic Motion Flashcards
Definition of simple harmonic motion
Oscillating motion where the acceleration is proportional to displacement and always opposite to the displacement
Describe the phase difference between displacement and velocity, and displacement and acceleration.
displacement is π/4 out of phase with velocity
displacement is π/2 out of phase with acceleration
Conditions for SHM for simple pendulum
Angle of displacement to vertical is very small
Acceleration is directly proportional to displacement and opposite
Conditions for SHM for mass-spring
Initial displacement is very small
The restoring force is opposite to the acceleration
How does the KE and PE vary with displacement
At the amplitude, PE = max
As it returns to equilibrium PE decreases and KE increases
At equilibrium KE = max
Definition of damping
When resistive forces causes the energy to dissipate and decrease the amplitude of the oscillations
Definition of light damping
When the time period is independent of the amplitude so each cycle takes the same length of time to die away.
Amplitude decreases the same fraction each cycle
Definition of critical damping
Just enough to stop the system completely from oscillating when displaced from equilibrium, so it immediately returns to equilibrium and stays
Definition of heavy damping
Displaced object returns to equilibrium very slowly and no oscillating motion occurs
What are the conditions of resonance?
When the applied frequency of the periodic force is equal to the natural frequency of the system.
When the periodic force is exactly in phase with the velocity of the oscillating system.
The amplitude increases each time when resonance happens
Definition of forced vibrations
The repeated upwards and downwards movement of the driver
The vibrations are at the frequency of the driven
Definition of resonance
The frequency of the forced vibrations are equal to the natural frequency
The displacement of the driver is π/2 out of phase with the driven oscillations
Definition of resonance
The frequency of the forced vibrations are equal to the natural frequency
The displacement of the driver is π/2 out of phase with the driven oscillations
