Oscillations (M5)

Question 1

Energy graph of an oscillation

Answer 1

PE U shape
KE upside down U shape
Total E straight line

Question 2

Free oscillation

Answer 2

The motion of a mechanical system displaced from its equilibrium position and then allowed to oscillate without and external forces.

Question 3

Forced oscillation

Answer 3

An oscillation in which a periodic driver force is applied to an oscillator.

Question 4

Phase difference

Answer 4

The difference in displacement between two oscillating objects or the displacement of an oscillating object at different times.
Symbol: phi

Question 5

Isochronos oscillator

Answer 5

An oscillator that has the same period regardless of amplitude.

Question 6

Defining equation for simple harmonic motion

Answer 6

SHM is a common kind of oscillating motion for which the acceleration of the object is given by
a = -w^2x where w^2 is constant.

Question 7

Damping

Answer 7

An oscillation is damped when an external force that acts on the oscillator has the effect of reducing the amplitude of its oscillations.

Question 8

Light damping

Answer 8

Damping that occurs when the damping forces are small and the period of the oscillations is almost unchanged.

Question 9

Heavy damping

Answer 9

Damping that occurs when the damping forces are large and the period of the oscillations increases slightly with the rapid decrease in amplitude.

Question 10

Resonance

Answer 10

The increase in amplitude of a forced oscillation when the driving frequency matches the natural frequency of the oscillating system.

Question 11

Natural frequency

Answer 11

The frequency of a free oscillation

Question 12

Driving frequency

Answer 12

The frequency of a driving force

Question 13

Oscillating motion

Answer 13

Repetitive motion of an object around its equilibrium position.

Question 14

Equilibrium position

Answer 14

The resting position of an object in an oscillation

Question 15

Angular frequency

Answer 15

A quantity used in oscillating motion equal to the product of frequency and 2pi
Symbol: w
w = 2pif
w = 2pi/T

Question 16

Derivation of v in an oscillation

Answer 16

1) Total energy = KE + PE so KE = TE - PE

2) PE = 1/2 kxx
PEmax = 1/2 kAA

3) KE = 1/2 kAA - 1/2 kxx
= 1/2 k(AA - xx)

4) F = ma
kx = ma = mwwx
k = mww
1/2 mvv = 1/2 mww(AA - xx)
vv = ww(AA - xx)
v = w rt(AA - xx)

5) v is max when x = 0
vmax = w rt(AA) = wA

Question 17

Energy-displacement graph for simple harmonic oscillator

Answer 17

Total energy: constant at max
KE: 0 to max to 0
PE: max to 0 to max