Progressive waves

Question 1

Define progressive waves

Answer 1

Waves that transfer energy away from a source, without transfer of matter

Question 2

What happens to particles in a wave which is moving to the right, ie. forwards.

Answer 2

The particles oscillate vertically but they do not move forwards or backwards

Question 3

What are the two types of progressive waves

Answer 3

Longitudinal

Transverse

Question 4

What causes a longitudinal wave

Answer 4

When the vibrations that cause them are parallel to the direction of energy transfer.

Question 5

What are 4 types of longitudinal waves

Answer 5

Sound waves

Ultrasound waves

Slinky waves

Seismic wave called P waves

Question 6

What is the result of logitudinal waves having vibrations parallel to the direction of energy transfer

Answer 6

Formation of compressions and rarefractions.

Question 7

How is a transverse wave created

Answer 7

when the vibrations causing them is at right angles to the direction of energy transfer.

Question 8

What is a type of transverse wave

Answer 8

Electromagnetic waves

Water waves

Question 9

Do Electromagnetic waves travel at different speeds

Answer 9

no all EM waves travel at speed of light in a vacumn

Question 10

What is the difference between the graphs of longitudinal waves and transverse waves

Answer 10

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

Question 11

what is the pressure when rarefraction happens

Answer 11

lowest pressures

Question 12

what is the pressure when compression happens

Answer 12

highest pressures

Question 13

What does a oscilliscope display

Answer 13

displays a voltage-time signal

Question 14

What can the oscilliscope be used as

Answer 14

as a voltmeter to display and measure the output from a mircophone or signal generator.

Question 15

What do we need to find the frequency of a wave displayed on an oscilloscope

Answer 15

Setting of the time base

Question 16

What is the time base on an oscilloscope measuring

Answer 16

The time taken for the luminous dot produced by the cathode ray tube to move a horizontal distance of 1cm across the oscilloscope screen.

Question 17

How do you find the time period, using distance between peaks and the time base setting on oscilloscope

Answer 17

time period = time base x distance between peaks

Question 18

How to reduce the uncertainty in the frequency measurement in oscilloscope

Answer 18

altering the time base such that one full wave has the widest possible range in the x direction.

Question 19

What happens if you turn off time base in oscilloscope, and whats the advantage of this for

Answer 19

Then the dot will no longer move across screen, this is good if you want to calculate the intensity of the sound waves.

Question 20

What is the vertical division represent in oscilloscope

Answer 20

a unit of voltage

Question 21

What does the sensitivity control do in oscilloscope

Answer 21

varies the volts per division,

eg. 20v/div ) less sensitive

to 5mV/div ) more sensitive