In deze les zitten 19 slides, met interactieve quizzen en tekstslides.
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Questions
You are in a breakout room as a group of four.
one of you shares their screen with this lesson up on it.
You are going to do questions, one of you writes down your answers in a word document.
Slide 1 - Tekstslide
Two formulas to calculate the speed of sound
speed=timedistance
speedofsound=wavelength⋅frequency
Slide 2 - Tekstslide
speed=timedistance
v=td
v: speed in m/s
d: distance in m
t: time in s
3=26
Slide 3 - Tekstslide
vs: the speed of sound (m/s)
λ: wavelength (m)
f: frequency (Hz)
speedofsound=wavelength⋅frequency
vs = λ • f
6=2⋅3
Slide 4 - Tekstslide
David drives 150 km in 2 hours. Calculate his average speed in km/h. Show your calculations.
Slide 5 - Open vraag
Fatima runs 200 meters in 40 seconds. Calculate her average speed in m/s. Show your calculations.
Slide 6 - Open vraag
There is a thunderstorm on its way. You see lightning. It takes 4 seconds before you hear the thunder. The speed of sound through air is 343 m/s. How far is the thunderstorm away?
Slide 7 - Open vraag
Someone makes a yell in a mountain valley. The closest mountain is at a distance of 411,6 meters away from them. The speed of sound in air is 343 m/s. How long will it take before they hear the echo?
A
4,8 seconds
B
3 seconds
C
5 seconds
D
2,4 seconds
Slide 8 - Quizvraag
Given:
v = 343 m/s
d = 411,6 m x 2 = 823,2 m
Asked:
How long will it take before they hear the echo?
Formula:
v = d/t —> t = d/v
Calculation:
t = 823,2 / 343 = 2,4 s
Someone makes a yell in a mountain valley. The closest mountain is at a distance of 411,6 meters away from them. The speed of sound in air is 343 m/s. How long will it take before they hear the echo?
Slide 9 - Tekstslide
A sound wave traveling through copper has a frequency of 400Hz. It has a wavelength of 5,65m.
Calculate the speed of sound in copper.
A
70.8 m/s
B
600 m/s
C
2260 m/s
D
2460 m/s
Slide 10 - Quizvraag
Given:
Frequency = 400 Hz
Wavelength = 5.65 m
Asked:
Calculate the speed of sound in copper
Formula:
Speed of sound = wavelength • frequency
Calculation:
Speed of sound = 400 x 5,65 = 2260 m/s
A sound wave traveling through copper has a frequency of 400 Hz. It has a wavelength of 5,65 m. Calculate the speed of sound in copper.
Slide 11 - Tekstslide
Slide 12 - Tekstslide
Explain why sound moves faster through a solid in compare to a gas?
Slide 13 - Open vraag
Questions 1
a) Write down the two formulas to calculate the speed of sound.
v= d /t — vs = λ • f
b) For each formula, write it out how to transform it for each variable.
v= d /t — d= v • t — t= d / v
vs = λ • f — λ= vs / f — f = vs / λ
Slide 14 - Tekstslide
Questions 2
Explain why doing the wavelength of a wave times the frequency of that wave results in the speed of that wave.
The frequency gives you the amount of waves per second.
The wavelength gives you the length of each wave in meters.
Multiplying the amount of waves per second times the length of each wave gives you the distance a sound wave travels in one second.
Slide 15 - Tekstslide
Questions 3
The speed of sound is 343 m/s in air at room temperature.
a) calculate the wavelength of a sound wave with a frequency of 20000 Hz.
λ = vs / f
vs = 343 m/s
f = 20000 Hz
λ = 343 / 20000 = 0.01715 m
b) calculate the frequency of a sound wave with a frequency of 20 Hz.
λ = vs / f
vs = 343 m/s
f = 20 Hz
λ = 343 / 20 = 17.15 m
Slide 16 - Tekstslide
Questions 4
a) A lighting flash strikes 4459 meters away from someone. 13 seconds later, the thunder is heard. Prove that the speed of sound is 343 m/s.
v= d /t
d = 4459 m
t = 13 s
v = 4459/13 = 343 m/s
b) If the wavelength of the thunder is 4,9 m, what would its frequency be?
f = vs / λ
vs = 343 m/s
λ = 4.9 m
f = 343 /4.9 = 70 Hz
Slide 17 - Tekstslide
Questions 5
A submarines sonar measures an echo 0.1 second after sending out a sound wave. The speed of sound through water is 1480 m/s. how close is the object the submarine detected?
v = d / t —> d =v • t
v = 1480 m/s
t = 0.1 —> 0.1/2= 0.05.
d = 1480 • 0.05 = 74 m
(you have to take into account that in echo sound has to travel there and back)
Slide 18 - Tekstslide
Questions 6
Calculate the frequency of a sound wave traveling through air with a wavelength of 0.6 m.