Module 4 - Waves (Wave Properties)

Question 1

Define a Progressive Wave

Answer 1

Any wave that transfers energy from one location to another due to oscillations of the medium through which energy is travelling

Question 2

What are the 2 ways waves can be classified

Answer 2

1. Mechanical and ElectroMagnetic Waves (EM)
2. Longitudinal and Transverse

Question 3

What is a Mechanical Wave

Answer 3

A wave that requires a particle-containing medium (some sort of matter) to propagate.

Question 4

Where do particle in a mechanical wave propogate

Answer 4

• About an equilibrium position

Question 5

What is an Electromagnetic Wave

Answer 5

A wave that does not require a particle-containing medium (some sort of matter) to propagate.

Question 6

What is a Transverse Wave

Answer 6

A wave that has oscillations that are perpendicular to the direction of energy transfer

Question 7

Examples of both Transverse and Longitudinal

Answer 7

Longitudinal:
- Sound
- Seismic P-waves

Transverse:
- Electromagnetic Waves
- Seismic S-Wave

Question 8

What is a Longitudinal Wave

Answer 8

A wave that has oscillations that are parallel to the direction of energy transfer

Question 9

What are unique features of Transverse Waves

Answer 9

• Oscillations perpendicular to direction of energy transfer
• Peaks and Troughs

Question 10

What are peaks and troughs

Answer 10

• The maximum positive (peak) and negative (trough) displacements on a transverse wave

Question 11

What are unique features of Longitudinal Waves

Answer 11

• Oscillations parallel to direction of energy transfer
• compressions and rarefactions

Question 12

What are common features for both Longitudinal and Transverse Waves

Answer 12

• An equilibrium position where the matter was before the wave
• Only energy is transferred and not matter

Question 13

Define Equilibrium Position

Answer 13

• The point around which a wave oscillates

Question 14

Define Frequency

Answer 14

The number of complete wavelengths/oscillations pass through a point per unit time

Question 15

Define Wavelength

Answer 15

The distance between two points oscillating in phase on adjacent waves

Question 16

Define Displacement

Answer 16

Distance in a given direction of a point on a wave from its equilibrium position

Question 17

Define Amplitude

Answer 17

• The maximum displacement of a point on a wave from its equilibrium position

Question 18

Define Time Period

Answer 18

The time it takes for one complete oscillation / or for one wavelength to pass a point

Question 19

Define Wave Velocity

Answer 19

Distance travelled by the wave per unit time

Question 20

Derive f = 1 / T

Answer 20

f = oscillations / time, T = time / oscillations, therefore:
fT = 1;
f = 1/T

Question 21

What does an s/d graph show

Answer 21

The displacement of all particles/points in a wave in one moment

Question 22

what does an s/t graph show

Answer 22

The displacement of one particle over a given time

Question 23

What are the conditions for two points on a wave to be in phase

Answer 23

They must be at the same position on a wave cycle
They must have the same motion direction

Question 24

What causes particles in a wave to be pulled back into equilibrium position

Answer 24

A restoring force acting on neighboring particles

Question 25

Determining the frequency of a wave using an oscilloscope

Answer 25

To determine the frequency of a wave, an oscilloscope is fed a signal, usually using a
microphone. The timebase on the oscilloscope can be set on the x axis to represent time and on
the y axis to represent the displacement. The time taken to complete one full oscillation can be
measured, and then used to find the frequency.