1.6 Vibrations

Question 1

When does simple harmonic motion occur?

Answer 1

When an object moves such that its acceleration is always directed toward a fixed point and is proportional to its distance from the fixed point

Question 2

Define phase and phase constant of an oscillation

Answer 2

The angle wt + E in the equation x = Acos(wt+E) is the phase of the oscillation, where the angle E is the phase constant

Question 3

When does a system undergo free oscillations?

Answer 3

A system undergoes free oscillations if it is set into motion then left with no external driving force

Question 4

When is a system damped?

Answer 4

A system is damped if free oscillations die away due to resistive forces

Question 5

Define over damping

Answer 5

If a system returns to its equilibrium position without oscillating

Question 6

Define under damping

Answer 6

If a system oscillates with the amplitude reducing gradually to 0

Question 7

Define critical damping

Answer 7

If a system returns to equilibrium as rapidly as possible without oscillating

Question 8

Define forced oscillation

Answer 8

When a sinusoidal driving force is applied to an oscillatory system, causing it to oscillate with the frequency of the driving force

Question 9

How does resonance work?

Answer 9

When the frequency of oscillation is very similar to the natural frequency of oscillation of the system, the amplitude of the oscillations is significantly greater