3.6.1.4 Forced vibrations and resonance

Question 1

What is a free oscillation?

Answer 1

One where there are only internal forces (no external forces) acting and there is no energy input.

It always occurs at its resonant frequency

Question 2

What are forced osillations?

Answer 2

Oscillations acted on by a periodic external force where energy is given in order to sustain oscillations

Question 3

Define resonance

Answer 3

When the frequency of the applied force to an oscillating system is equal to its natural frequency, there is a large increase in amplitude (up to a maximum)

Question 4

What are the effects of damping on resonance?

Answer 4

Damping reduces the amplitude of resonance vibrations (peak of curve lowers).
Resonance peak broadens
Resonance peak moves slightly to the left of the natural frequency when heavily damped