H210 Oscillations Flashcards
(14 cards)
Define oscillation.
An oscillation is a to-and-fro motion between two limits.
Define free oscillation
Free oscillations are oscillations with constant amplitude without energy loss or gain as there are no driving or resistive forces acting on it.
Define natural frequency.
Natural frequency is the frequency at which a body will vibrate when there are no driving or resistive forces acting on it.
Define simple harmonic motion.
Simple harmonic motion is a type of oscillatory motion where the acceleration is diectly proportional to displacement from the equilibrium position and directed opposite to displacement.
State the formula for acceleration in simple harmonic motion.
a = -W^2x’
State the formula for velocity of a body under simple harmonic motion.
v = +- W square root(x0^2 - x^2)
State the formula for maximum velocity.
v0 = wx0
State the formula for maximum acceleration.
a0 = w^2x0
State the formula for Ek with displacement.
Ek = 1/2mw^2(x0^2-x^2)
Define damped oscillations.
Damped oscillations are oscillations in which the amplitude decreases with time as a result of dissipative forces that reduces the total energy of the oscillations.
What should a good suspension system in a car have?
A good suspension system should:
1. partially absorb the impact of a bump in the road for the comfort of passengers
2. return to equilibrium quickly
Define forced oscillations.
Forced oscillations are oscillations where there is continuous input of energy by external periodic force that maintains the oscillation amplitude.
How does forced oscillations lead to resonance?
As the frequency of the external driver increases from zero, the amplitude of the forced oscillation increases. The amplitude reaches a maximm when the external driving force matches that of the natural frequency of the system. Beyound that point, amplitude decreases with further increases in driving frequency,
Define resonance
Resonance occurs when the frequency of the external driving force equals to natural frequency of the system and the resulting amplitude is maximum because there is maximum rate of transfer of energy from the external driver to the oscillating system.
