Chapter 17. Oscillations

Question 1

Define period

Answer 1

The time taken for one complete oscillation or vibration

Question 2

Define frequency

Answer 2

The number of complete oscillations per unit time

Question 3

What is the relationship between frequency and period?

Answer 3

Frequency, f = 1 / T , period

Question 4

What are is the unit of frequency and its equivalence?

Answer 4

Hertz, 1 Hz = 1 s^-1

Question 5

Define amplitude

Answer 5

The maximum displacement from equilibrium position

Question 6

What is meant by isochronous?

Answer 6

The ability of an oscillator to maintain a constant period despite change in amplitude

Question 7

Define simple harmonic motion

Answer 7

The motion of a particle about a fixed point such that its acceleration a is proportional to its displacement x from the fixed point and is in the opposite direction, a = -ω²x

Question 8

What is the solution for the equation of simple harmonic motion?

Answer 8

x = x₀sinωt

Question 9

What are the formulae for velocity for SHM?

Answer 9

v = v₀cosωt when x = x₀sinωt

v₀= x₀ω

V max = +/- ω * root of x max squared minus x squared

Question 10

What is the formula for acceleration?

Answer 10

a = −a0 sinωt when x = x0 sin ωt

Question 11

Define free oscillation

Answer 11

A particle is said to be undergoing free oscillations when the only external force acting on it is the restoring force.

Question 12

What are the effects of damping?

Answer 12

» the amplitude of oscillation at all frequencies is reduced
» the frequency at maximum amplitude shifts gradually towards lower frequencies
» the peak becomes flatter.

Question 13

Explain what is meant by resonance

Answer 13

Resonance occurs when the natural frequency of vibration of an object is equal to
the driving frequency, giving a maximum amplitude of vibration.