Waves Flashcards
State what happens to the amplitude and wavelength of a wave if pitch is increased at constant loudness [1]
amp same
wavelength decrease
Explain what happens as wavelength strikes a boundary [2]
new waves generated
same speed/frequency
angle of incidence=angle of reflection
Explain refraction in shallower area [3]
wavefront refracted, changes direction
in shallower area shorter wavelength
wave spreads in shallower area
all points from original wave move to corresponding points on new wave
Explain how a diagram shows that water waves travel more slowly in shallow water than in deep water [3]
wavelength smaller
frequency constant
speed=freqxwavelength
State how longitudinal wave changes if
a) sound had higher frequency [1]
b) if sounds were louder [1]
a) more compressions and rarefractions
b) closer layers at compressions, farther layers at rarefractions
Explain why sound waves are described as longitudinal [2]
particles vibrate
in direction of propagation
Boat passes over region where reflection of sound waves weaker. State what happens to the amplitude and pitch [2]
decrease
no change
State and explain how wavelength of sound in air compares with wavelength of sound in water [1]
less and travels less far in same time
A dentist takes an X-ray photograph of a patoemt’s teeth. Explain why it is safe for the patient to be close to the source, but dentist must stand away from source.
xrays harmful
.
patient rarely exposed
low total dose on patient
dentist frequently exposed
Speed of sound in water
900-2000 m/s
State one similarity between sound of frequency 750Hz and ultrasound [1]
both are longitudinal
Explain what is meant by the term transverse wave motion [3]
transimission of energy and no transfer of matter
direction of vibration of particles
perpendicular to direction of wave
