Topic 4 Flashcards
Done except for few specpoints
4.1
What is a wave
Method of transferring:
-E & info
-From a source
-w/o matter
4.2
Define the term compression
Areas in the wave where the particles are close together
4.2
Define the term rarefraction
Areas in the wave where the particles are far apart
4.2
Describe evidence that with water and sound waves it is the wave and not the water or air itself that travels
-Water/air molecules oscillate in place as E passes through
-Molecules themselves don’t travel w/ wave
4.3
Define the term frequency. What is it measured in?
-No. of waves passing a given point/s
-Hz (Hertz)
4.3
What is the equation for working out the frequency of a wave?
f=1/T
4.3
Define the term wavelength
What is it measured in?
-Distance from peak to peak or trough to trough
-m (metres)
4.4
Define the term amplitude
What is it measured in?
-Distance from rest position to peak or trough
-m (metres)
4.4
Define the term period
What is it measured in?
-t for 1 wave to pass given point
-s (seconds)
4.4
What is the equation for working out the time period of a wave?
T=1/f
4.4
Define the term wave speed. What is it measured in?
Total distance covered by wave in given time period
(m/s)
4.5
Compare transverse and longitudinal waves
Transverse - Oscillation of particles PERPENDICULAR to direction of wave
WHEREAS
Longitudinal - Oscillation of particles PARALLEL to direction of wave
4.5
State 4 examples of transverse waves
-Sea/water waves
-Light waves
-Other electromagnetic waves
-Some seismic waves
4.5
State 2 examples of longitudinal waves
-Sound waves
-Some seismic waves
4.6
State 2 equations for wave speed (velocity)
State their units
Wave speed(m/s) = frequency(Hz) × wavelength(m)
v=f×λ
Wave speed(m/s) = distance(m) ÷ time(s)
v=x/t
4.7
Describe how to measure the velocity of sound in ripples on water surfaces
-Use ripple tank w/ vibrating bar
-Bar connected to power pack
-Vibrates -> waves on water surface
-Lamp above ripple tank
-White paper under w/ ruler alongside
-Light shines thru water -> image of waves on paper
-Record w/ phone
-Freeze image & measure λ
-Find f: record timer + waves & watch in slow motion
-Count no. of waves passing point in 1 sec
-v=f×λ
4.7
Describe how to measure the velocity of sound in ripples on water surfaces
-Select wave
-Measure tank length
-Measure t takes to move tank length
-s=d/t
4.8P
The sound wave released from a ship took 0.12 seconds to return. The speed of sound in water is 1500 m/s. What was the depth of the sea?
90m
Define the term oscillation
VIBRATION of particles back and forth around an EQUILIBRIUM point
What are the colours of visible light?
Red
Orange
Yellow
Green
Blue
Indigo
Violet