general properties of waves

Question 1

What is a wave?

Answer 1

• A wave is a disturbance that propagates through space, transferring energy with it but not matter
• the wave source is a vibration or oscillation. This can be periodic

Question 2

Transverse waves

Answer 2

• A transverse wave has a direction of vibration of particles that is perpendicular to the direction of wave travel
• examples: electromagnetic waves (eg visible light, X-rays, ultraviolet radiation), rope waves

Question 3

longitudinal waves

Answer 3

• a longitudinal wave has a direction of vibration of particles that is parallel to the direction of wave travel
• examples: sound

Question 4

crest

Answer 4

a crest is the highest point of a transverse wave

Question 5

trough

Answer 5

a trough is the lowest point of a transverse wave

Question 6

amplitude

Answer 6

• the maximum displacement of a point from its rest position
• SI unit: metre (m)

Question 7

wavelength

Answer 7

• the shortest distance between any two points of a wave which are in phase
• SI unit: metre (m)

Question 8

period T

Answer 8

• the time taken to produce one complete wave
• SI unit: seconds (s)

Question 9

frequency f

Answer 9

• the number of complete waves produced per unit time
• SI unit: hertz (Hz)

Question 10

relationship between frequency and period

Answer 10

f = 1/T

Question 11

wave speed v

Answer 11

• the distance travelled by the wave per unit time

Question 12

relationship between wave speed, frequency and wavelength

Answer 12

speed = frequency x wavelength

Question 13

wavefront

Answer 13

• a wavefront is an imaginary line on a wave that joins all adjacent points that are in a phase
• the direction of wave travel is always perpendicular to the wavefront
• the distance between two successive wavefronts is the wavelength