Progressive waves Flashcards
Define progressive waves
Waves that transfer energy away from a source, without transfer of matter
What happens to particles in a wave which is moving to the right, ie. forwards.
The particles oscillate vertically but they do not move forwards or backwards
What are the two types of progressive waves
Longitudinal
Transverse
What causes a longitudinal wave
When the vibrations that cause them are parallel to the direction of energy transfer.
What are 4 types of longitudinal waves
Sound waves
Ultrasound waves
Slinky waves
Seismic wave called P waves
What is the result of logitudinal waves having vibrations parallel to the direction of energy transfer
Formation of compressions and rarefractions.
How is a transverse wave created
when the vibrations causing them is at right angles to the direction of energy transfer.
What is a type of transverse wave
Electromagnetic waves
Water waves
Do Electromagnetic waves travel at different speeds
no all EM waves travel at speed of light in a vacumn
What is the difference between the graphs of longitudinal waves and transverse waves
transverse waves - x axis = time or distance , y axis = displacement
longtudinal waves - x axis = distance, y axis = pressure/displacement, max,normal,min and compression and rarefractions
what is the pressure when rarefraction happens
lowest pressures
what is the pressure when compression happens
highest pressures
What does a oscilliscope display
displays a voltage-time signal
What can the oscilliscope be used as
as a voltmeter to display and measure the output from a mircophone or signal generator.
What do we need to find the frequency of a wave displayed on an oscilloscope
Setting of the time base
What is the time base on an oscilloscope measuring
The time taken for the luminous dot produced by the cathode ray tube to move a horizontal distance of 1cm across the oscilloscope screen.
How do you find the time period, using distance between peaks and the time base setting on oscilloscope
time period = time base x distance between peaks
How to reduce the uncertainty in the frequency measurement in oscilloscope
altering the time base such that one full wave has the widest possible range in the x direction.
What happens if you turn off time base in oscilloscope, and whats the advantage of this for
Then the dot will no longer move across screen, this is good if you want to calculate the intensity of the sound waves.
What is the vertical division represent in oscilloscope
a unit of voltage
What does the sensitivity control do in oscilloscope
varies the volts per division,
eg. 20v/div ) less sensitive
to 5mV/div ) more sensitive
