3.3 Wave Systems

Question 1

What is the beats formula?

Answer 1

fᵇ = f¹ - f²

Question 2

What is a wave?

Answer 2

A wave is a regular vibration that carries energy

Question 3

What are the two basic kinds of waves?

Answer 3

Transverse waves and longitudinal waves

Question 4

How would you create a transverse wave on a slinky?

Answer 4

Keep one end fixed and shake the other end from side to side

Question 5

How would you create a longitudinal wave on a slinky?

Answer 5

Keep one end fixed and pushing the other end in and out

Question 6

What is the frequency of a wave?

Answer 6

f - The number of oscillations per unit time (measured in hertz - hz)

Question 7

What is the period of a wave?

Answer 7

T - The time it takes for one complete oscillation (measured in seconds - s)

Question 8

What is the speed of a wave?

Answer 8

v - The distance travelled per unit time by the wave (measured in meters per second - ms⁻¹)

Question 9

What is the relationship between amplitude and wave energy?

Answer 9

The bigger the amplitude the more energy the wave carries

Question 10

What are electromagnetic waves?

Answer 10

Electromagnetic waves are transverse waves that travel at the speed of light in a vaccuum

Question 11

What are the different types of electromagnetic wave listed from low frequency to high frequency?

Answer 11

Radio
Microwaves
Infrared
Visible (ROYGBIV)
Ultra Violet
X Rays
Gamma Rays

Question 12

What are sound waves?

Answer 12

Sound waves are longitudinal waves consisting of a series of compressions and rarefactions

Question 13

What can produce sounds waves?

Answer 13

• A string which is plucked (guitar), bowed (violin) or hit (piano)
• A column of air in a wind instrument or organ pipe

Question 14

What is the amplitude of the sound?

Answer 14

The amplitude of the sound is the maximum displacement of the air particles from their rest position

Question 15

What is the relationship between the amplitude of a sound wave and the volume?

Answer 15

The greater the amplitude of the sound wave, the louder the sound

Question 16

What are the four types of behaviours of all types of waves?

Answer 16

Reflection, refraction, diffraction and interference

Question 17

When does reflection occur?

Answer 17

Reflection occurs when a wave bounces from the surface of an obstacle

Question 18

What happens to the properties of a wave after it is reflected?

Answer 18

None of the properties are changed by reflection. The wavelength, frequency, period and speed are the same before and after reflection. The only change is the direction in which the wave is travelling

Question 19

When does refraction occur?

Answer 19

Refraction occurs when a wave moves from one material to another

Question 20

What happens to the properties of a wave after it is refracted?

Answer 20

The speed and wavelength are changed by refraction. The frequency of the wave stays the same. The direction in which the wave is travelling may or may not be changed by refraction

Question 21

When does diffraction occur?

Answer 21

Diffraction occurs when a wave passes around an object or through a gap (called a slit or an aperture)

Question 22

When a wave passes through a gap, when is the diffraction effect the greatest?

Answer 22

When a wave passes through a gap the diffraction effect is greatest when the width of the gap is about the same size as the wavelength of the wave