Simple Harmonic Motion

Question 1

Define SHM

Answer 1

motion where:
acceleration is directly proportional to displacement
acceleration is always acting in the opposite direction to displacement

Question 2

Define a free vibration

Answer 2

the oscillation of an object with no transfer of energy to or from the surroundings

Question 3

When is there maximum velocity for a simple pendulum?

Answer 3

when it’s at the equilibrium position

Question 4

What is a forced vibration?

Answer 4

the oscillation of an object due to an external periodic driving force

Question 5

Define damping

Answer 5

a force which causes an oscillating system to lose energy and so causes the amplitude of the object’s oscillations to decrease

Question 6

What is light damping?

Answer 6

when the system settles in equilibrium after many oscillations

Question 7

Give an example of light damping

Answer 7

a pendulum in air

Question 8

What is critical damping?

Answer 8

when the system settles in equilibrium in minimum time

Question 9

What is Resonance?

Answer 9

when the frequency of the driving force equals the natural frequency of the system, a large (increase in) amplitude is seen

Question 10

What is the phase difference between the driving frequency and the natural frequency when the driving frequency equals 0?

Answer 10

0

Question 11

What is the phase difference between the driving frequency and the natural frequency when the system is at resonant frequency?

Answer 11

π/2

Question 12

What is the phase difference between the driving frequency and the natural frequency when the driving frequency tends to infinity / when the amplitude tends to zero?

Answer 12

π

Question 13

What are the conditions for SHM?

Answer 13

1. acceleration ∝ displacement from the equilibrium point (a∝x)
2. displacement and acceleration are in opposite directions (a∝ -x)