Waves

Question 1

How do you measure the wavelength

Answer 1

The distance between two peaks

Question 2

How do you measure amplitude

Answer 2

The maximum displacement of the wave from the centreline (the peak to the centreline)

Question 3

What is Hz used to measure

Answer 3

Frequency

Question 4

What is the difference between transverse and longitudinal waves

Answer 4

Transverse has perpendicular direction of energy transfer and movement of particles, whereas Longitudinal has paraLLeL

Question 5

What do waves transfer and what do they not transfer

Answer 5

They transfer energy and information, but NOT matter

Question 6

What is the equation for wave speed

Answer 6

Wave speed = frequency x wavelength

v = f λ

Question 7

What is the relationship between frequency and time period

Answer 7

Frequency = 1/time period

Question 8

What is the wavefront

Answer 8

A line connecting the peaks of waves, but across the tops of waves that are next to each other. Imagine a 3D view of a wave, then imagine many waves just like that one next to it. The wavefront is the line that connects the peaks. See camera roll 24th October for diagram (ignore the peter crouch picture - i hope by now he has a really good evo that i put him into)

Question 9

What is the period of a wave

Answer 9

The time taken for one complete wave to pass a point

Question 10

What is frequency

Answer 10

How often a peak is recorded

Question 11

What is a rarefaction

Answer 11

An area where the frequency is lower than normal in a longitudinal wave

Question 12

What is an area of compression on a longitudinal wave

Answer 12

An area where the frequency is higher than normal

Question 13

What is the wavelength of a longitudinal wave

Answer 13

The distance between two consecutive rarefactions/compressions

Question 14

What are peaks and troughs comparable to in longitudinal waves

Answer 14

The distance between the midpoint between two compressions and the nearest compression

Question 15

What is the range for human hearing

Answer 15

20 Hz - 20,000 Hz

Question 16

What does the pitch of a sound depend on

Answer 16

The frequency of the vibration of the sound

Question 17

Describe an experiment for measuring the speed of sound in air

Answer 17

Required equipment: 2 people, a trundle wheel/tape measure and a stopwatch
1. Get 2 people
2. Stand far away from each other
3. Get one person to clap, the other uses a stopwatch to record the time between the person clapping and the second person hearing the sound
4. Repeat this 5 times for accuracy
5. Average out the time
6. Measure the distance between the people using a tape measure or trundle wheel
7. Using the equation speed = distance/time, calculate the speed of sound to be around 340m/s

Question 18

What does the loudness of a sound depend on

Answer 18

The amplitude

Question 19

Fill in the blank: a large sound has a large _______

Question 20

Fill in the blank: a high pitched sound has a _______ frequency

Answer 20

High

Question 21

Fill in the blank: a high pitched sound has a high ______

Answer 21

Frequency

Question 22

How can an oscilloscope and microphone be used to display a sound wave

Answer 22

A microphone converts sound energy into electrical energy in the form of electronic signals. A computer or an oscilloscope can be used to display these electronic signals, which show the same changes in amplitude and frequency as the sound waves.

Question 23

How to read data from an oscilloscope

Answer 23

Time period: the distance between two peaks is the time period (NOT THE WAVELENGTH). For example if each square is representing 1 millisecond and the distance between the two peaks is 4 squares, then the time period of the inputted sound wave is 4 milliseconds. This can then be used to find frequency ( f = 1/T)

Amplitude: measure the distance of the peak from the rest point (centreline) THEN YOU MUST look at how many volts are per each square, then multiply that number by the distance of the peak from the rest point, to get the amplitude of the inputted sound. E.g. if distance of peak from rest point = 4cm and volts per square = 6, amplitude = 24

Question 24

What is sound below 20Hz called

Answer 24

Infrasound

Question 25

What is sound above 20,000 Hz called

Answer 25

Ultrasound

Question 26

How are sound waves used for pregnant mothers

Answer 26

They can scan pre-natal babies to show size, position, heartbeat and organ development.