An underwater sound source emits waves of frequency 30 kHz in all directions. How does the intensity of the waves (in Watts/m2) vary with distance r from the source?a) 1/r^3 b) 1/r^2 c) 1/r d) None of above
When an underwater sound source emits waves of frequency 30 kHz in all directions, the intensity of the waves (in Watts/m2) vary with distance r from the source by the relation 1/r²
As the intensity mechanical sound wave is inversely proportional to the square of the distance from the source, therefore the correct option is B.
What is the Wavelength?
Wavelength can be understood in terms of the distance between any two similar successive points across any wave for example wavelength can be calculated by measuring the distance between any two successive crests.
It is the total length of the wave for which it completes one cycle.
The intensity of a mechanical wave is inversely proportional to the square of the distance from the source.
An underwater sound source emits waves of frequency of 30 kHz in all directions, the intensity of the waves (in Watts/m2) varies with distance r from the source by the relation 1/r², therefore the correct option is B.
How does the geosphere interact with the hydrosphere
Plants (biosphere) draw water (hydrosphere) and nutrients from the soil (geosphere) and release water vapor into the atmosphere.
Air contains 78.08% nitrogen, 20.095% oxygen, and 0.93% argon. calculate the partial pressure of oxygen if the total pressure of the air sample is 1.7 atm.a.
partial pressure in a mixture of two or more gases will be given by formula
= mole fraction of gas * total pressure
now here mole fraction is same as percentage of gas in the mixture
Now mole fraction of oxygen is 0.20095 (20.095%)
now here pressure of oxygen in the mixture is given as
so pressure due to oxygen in the mixture will be 0.342 atm
The Richter scale is used to determine how strong the earthquake is (magnitude) of the earthquake. It touches the ground and feels the earth shaking. With the momentum of the earth shaking the device the needle on the device moves creating a wave looking line. According to the theory of plate tectonics, what happens at transform, divergent and convergent boundaries? On which of these boundary types would a volcano most likely take place, and why?
convergent, because it is where the tectonic plates shove themselves together usually resulting in a mountain or volcano
In plate tectonics theory, transform boundaries occur when two plates slide past each other, divergent boundaries occur when two plates move away from each other, and convergent boundaries occur when two plates collide. A volcano is most likely to occur at a divergent boundary because the plates move away from each other, allowing magma from the mantle to reach the surface and create new crust.
In plate tectonics theory, Transform boundaries occur when two plates slide past each other horizontally, creating earthquakes. Divergent boundaries occur when two plates move away from each other, creating volcanic activity.
Convergent boundaries occur when two plates collide, and depending on the type of plates involved, can result in volcanic activity as one plate is forced beneath the other.
A volcano is most likely to occur at a divergent boundary because the plates move away from each other, allowing magma from the mantle to reach the surface and create new crust.
The Richter scale indicates the magnitude of an earthquake. The figure drawn by the needle during shaking is an outcome of earthquake's energy. This energy is what results in seismic waves travelling through various layers of earth causing shaking on the surface.
Learn more about Plate tectonics and volcanoes here:
A javelin is thrown in the air. Its height is given by ( ) 1 2 8 6 20 h x x x = − + + , where x is the horizontal distance in feet from the point at which the javelin is thrown. a. How high is the javelin when it was thrown? b. What is the maximum height of the javelin? c. How far from the thrower does the javelin strike the ground?'
The maximum height, the location on the ground and the initial vertical height of the javelin is required.
Part A A microphone is located on the line connecting two speakers hat are 0 932 m apart and oscillating in phase. The microphone is 2 83 m from the midpoint of the two speakers What are the lowest two trequencies that produce an interflerence maximum at the microphone's location? Enter your answers numerically separated by a comma
The distance between two speakers (d) = 0.932 m
The distance of the microphone from the midpoint = 2.83 m
Thus, distance of microphone from the nearest speaker (L) = 2.83 - (0.932/2) = 2.364 m
also, the distance of the microphone from the farther speaker (L') = 2.83 + (0.932/2) = 3.296 m
The path difference is calculated as
L' - L = d = 0.932 m
Now,for a maxima to be produced at the microphone, the waves must constructively interfere.
for this to happen the path difference should be integral multiple of the wavelength.
hence, the largest wavelength will be for n = 1,
0.932 = 1 × λ
λ = 0.932 m
now, the velocity of sound is given as c = 343 m/s
thus, the frequency will be
on substituting the values, we get
now, the 2nd largest wavelength will be for n = 2
0.932 = 2 × λ
λ = 0.466
thus, the frequency will be
hence, these are the lowest first two frequencies.