Flashcards
Damping and Resonance
Cards in this deck (16)
- 1When does damping occur?When resistance is added to the motion of an oscillator
- 2When damping occurs, what is taken out of the system?Energy
- 3What does underdamped mean?System oscillates before coming to a stop
- 4What does critically damped mean?The smallest amount of damping required for a system not to oscillate
- 5What does overdamped mean?Any more damping that critically damped
- 6Graph of underdamping, critical damping and overdamping:
- 7How to check if damping graph is exponential:1. Decide on value for "change in x-axis quantity." Pick 4 x-values (they should take up a large portion of the graph). They should also change equally
2. Find the y-values at these x-values
3. Check if y1/y2 = y2/y3 = y3/y4 , and if so it's exponential (note doesn't have to be exact) - 8What is free oscillation?No force acting except internal forces
No energy input (following initial displacement)
: Oscillates at it's natural frequency - 9What is forced oscillation?Oscillator is acted on by periodic external force
Energy given periodically by an external force
: Provides driving frequency - 10What is Resonance?Where the natural frequency = the driving frequency (or approximately)
- 11What does resonance cause?Amplitude of vibration to rapidly increases to a maximum value
- 12How do we answer a question on resonance?State whats providing the driving frequency and the object whose natural frequency is being matched
(e.g. washing machine: frequency of drum spinning (driving) = frequency of whole washing machine (natural)) - 13Amplitude against driving frequency graph:
- 14Set up used for graph above:
- 15On the graph, we need to know the damped line is....Lower and the peak is more to the left
- 16If the masses bang when oscillating, it means.....a=g
(at top = a(max))