SHM Flashcards
State the conditions needed for SHM
Acceleration must be proportional to the displacement. Acceleration must be in opposite direction to displacement.
What are free vibrations?
when the amplitude is constant and no frictional forces are present.
What shape is the displacement/time graph?
cos
What shape is the velocity/time graph?
-sin
What shape is the acceleration/time graph?
-cos
How can you reduce the frequency of oscillation of a loaded spring?
adding extra mass
using weaker springs
What is light damping?
time period is independent of amplitude. so each cycle takes the same amount of time as the oscillations die away.
What is critical damping?
The oscillating system returns to equilibrium in the shortest possible time. e.g. car suspension
What is heavy damping?
the damping is so strong that the displaced object returns to equilibrium much more slowly than if the system was critically damped.
What is a periodic force?
A force applied at regular intervals to keep system oscillating
What is natural frequency?
the frequency of a system oscillating without a periodic force being applied
What happens when a periodic force is applied?
The oscillating system undergoes forced vibrations (forced oscillations)
What is resonance?
When the periodic applied force is exactly in phase with the velocity of the oscillating system.
What is the resonant frequency?
the frequency at the maximum amplitude
What happens when the damping is lighter?
the closer the resonant frequency is to the natural frequency of the system.
the larger the maximum amplitude becomes at resonance.
