Definitions

Question 1

What is frequency?

Answer 1

Number of complete wave cycles per second. (Hertz, Hz)

Question 2

What is wavelength?

Answer 2

The displacement between one point and the next point consecutive point in phase

Question 3

What is time period?

Answer 3

Time taken for one complete oscillation. (Seconds, s)

Question 4

What is wave speed?

Answer 4

Rate of movement of the wave. (Meters per second, ms^-1)

Question 5

Define a longitudinal wave.

Answer 5

A longitudinal wave consists of particles that oscillate parallel to the direction of propagation of the wave with compressions and rarefactions.

Question 6

Define a transverse wave.

Answer 6

A transverse wave consists of oscillations perpendicular to the direction of propagation of the wave.

Question 7

The principle of superposition.

Answer 7

When two or more waves combine and the resulted amplitude is the sum of the separate amplitudes

Question 8

Waves that have a constructive superposition have what path difference and phase difference?

Answer 8

0λ, 1λ, 2λ… nλ. 2π radians or 0π radians, 0 degrees, 360 degrees…
In phase

Question 9

Waves that have a destructive superposition are said to have what path and phase difference?

Answer 9

1/2λ, 3/2λ, 5/2λ…. (n+1/2)λ
1π radians, 180 degrees
Antiphase

Question 10

Define coherent.

Answer 10

Same frequency and unchanging phase difference.

Question 11

What is fundamental frequency?

Answer 11

This is the lowest frequency that can produce a stationary wave. The length of the loop is equal to half of a wavelength.

Question 12

If a fundamental harmony has a frequency of 3.6Hz what is the frequency of a fourth harmonic?

Answer 12

14.4

Because 3.6 * 4= 14.4

Question 13

What waves does sonar use?

Answer 13

Sound waves

Question 14

What waves do radar use?

Answer 14

Radio waves

Question 15

What happens to waves?

Answer 15

Can be transmitted, reflected or absorbed.

Question 16

What is intensity?

Answer 16

A measure of the amount of energy (incident at 90degrees) per second per unit area.

Question 17

A wave is refracted towards the normal when…

Answer 17

The medium 2 is optically more dense.

Question 18

What is refraction?

Answer 18

A change in direction due to a change in speed as it travels from one medium to another ( different optical density).

Question 19

The shorter the wavelength…

Answer 19

The greater the refractive index

Question 20

What are the colours of a rainbow?

Answer 20

Red
Orange
Yellow
Green
Blue
Indigo
Violet

Question 21

What is amplitude?

Answer 21

Maximum displacement from equilibrium. (Meters, m)

Question 22

What are ultrasound waves?

Answer 22

Are sound waves that have too high frequency for humans to hear (20,000 Hz).

Question 23

What is reflection?

Answer 23

The wave is bounced back when it hits a boundary.

Question 24

What is the critical angle?

Answer 24

The angle of incidence that gives an angle of refraction of 90

Question 25

Difference between stationary waves and progressive waves

Answer 25

Stationary -stores vibrational energy, progressive -transmit vibrational energy. Stationery -amplitude varies, progressive -amplitude is constant. Stationery- all points between any two adjacent nodes are in phase, Progressive -phase varies smoothly with distance along the path of the wave. Stationery -notes are half a wavelength apart, antinodes are midway between antinodes, progressive- no nodes or antinodes.