Physics, 04.03.2021 01:40, golderhadashaowtatz
PLEASE PLEASE HELP ME OUT, 45 POINTS+BRAINLIEST
Imagine that a firecracker explodes sending a sudden burst of sound waves traveling out in all directions from the single point where the firework exploded. The series of spheres below illustrates the leading edge of that sound wave as it travels outward over time.
Let’s suppose that the total energy transferred to the sound wave is 10.0 Joules, which is spread evenly in all directions. After 1 second, the sound energy is still concentrated in a relatively small area – the surface area of the sphere shown at far left. Because the energy is concentrated in such a small space, it will still sound very loud to anyone who is close enough to hear it after just 1 second. As time goes on, the sound spreads out over a larger and larger sphere.
In this activity, you will be asked to calculate the surface area of each sphere shown above using the information in the table below. (Recall that the equation for the surface area of a sphere is A = 4 π r 2). You will then calculate how intensity of sound over time by taking the total energy (10.0 Joules) and dividing it by the surface area to determine the energy per square kilometer.
Time
(Seconds)
Total Energy
(Joules)
Radius
(Kilometers)
Surface Area
(km2)
Intensity
(Joules / km2)
1.00
10.0
0.34
1.45
6.90
2.00
10.0
0.68
3.00
10.0
1.02
4.00
10.0
1.36
5.00
10.0
1.70
First calculate the surface area for each of the spheres above, recording your data in the table. The first calculation has been performed for you. (3 points)
Then calculate the intensity of the sound by taking the total energy and dividing by the surface area for each sphere. (3 points)
Finally, answer the three questions below.
Reflection Questions
What general pattern do you notice in the intensity of sound for a listener who is farther and farther away from the initial firework blast? Does this make sense? Why/why not? (5 points)
In your own words, explain why the intensity of sound falls off with the square of the distance from the source of sound. (5 points)
Explain why everyone in a classroom can hear one person speaking, but why a microphone and speaker must be used in a large concert auditorium. (5 points)
Answers: 1
Physics, 22.06.2019 06:40, PerfectMagZ
Alinearly polarized electromagnetic wave has an average intensity of 196 w/m^2. this wave is directed towards two ideal polarizers (in real polarizers, transmission is also effected by reflection and absorption). polarizer a is oriented with its transmission axis at an angle of θ_1=20.8∘ with the incident electric field. polarizer b has its axis at an angle of θ_2=63.0∘ with the incident electric field. what is the average intensity of the wave after it passes through polarizer a? what is the average intensity of the wave after it passes through polarizer b? suppose that the two polarizers a and b are interchanged. what would the average intensity be after passing through both polarizers?
Answers: 2
Physics, 22.06.2019 09:30, looloo273
Asap i'm in class rn a 1,000-kg car is traveling 20 m/s on a flat stretch of road. it gets to a hill and coasts uphill until it stops. how high up the hill does the car travel? givens: equation: 1/2mv2initial=mghfinal solve for h. plug & chug, label.
Answers: 2
Physics, 22.06.2019 10:50, dontcareanyonemo
The temperature at a point (x, y) is t(x, y), measured in degrees celsius. a bug crawls so that its position after t seconds is given by x = 6 + t , y = 8 + 1 3 t, where x and y are measured in centimeters. the temperature function satisfies tx(3, 9) = 5 and ty(3, 9) = 4. how fast is the temperature rising on the bug's path after 3 seconds? (round your answer to two decimal places.)
Answers: 3
PLEASE PLEASE HELP ME OUT, 45 POINTS+BRAINLIEST
Imagine that a firecracker explodes sending a sudde...
Mathematics, 10.12.2020 02:30
French, 10.12.2020 02:30
English, 10.12.2020 02:30
World Languages, 10.12.2020 02:30