It would take 25 seconds.
200/8 = 25
The distance at which the sound level is 100 dB is 30m.
<h3>
What is distance?</h3>
Distance is a measurement of how far apart two objects or locations are. Distance in physics or common language can refer to a physical length or an estimate based on other factors (e.g. "two counties over"). |AB| is a symbol that can be used to represent the distance between two points. "Distance from A to B" and "Distance from B to A" are frequently used interchangeably. A distance function or metric is a technique to describe what it means for elements of some space to be "close to" or "far away" from each other in mathematics. It is a generalization of the idea of physical distance. Distance is a non-numerical unit of measurement in psychology and other social sciences.
Explanation:
We anticipate the radial distance to be 10 times greater, or 30 m, when the intensity is reduced by 20 dB, or by a factor of 102. A further 90 dB reduction might translate to an additional factor of 104.5 in terms of distance, or roughly 3030000m or 1000 miles. We measure sound intensity using the inverse square law and the decibel scale definition. According to the sound level definition,
β=10log![(\frac{1}{10^{-12}W/m^{2} } )](https://tex.z-dn.net/?f=%28%5Cfrac%7B1%7D%7B10%5E%7B-12%7DW%2Fm%5E%7B2%7D%20%20%7D%20%29)
We can compute the intensities corresponding to each of the levels mentioned as
![I=[10^{\frac{\beta }{10} } ]10^{-12} W/m^{2}](https://tex.z-dn.net/?f=I%3D%5B10%5E%7B%5Cfrac%7B%5Cbeta%20%7D%7B10%7D%20%7D%20%5D10%5E%7B-12%7D%20W%2Fm%5E%7B2%7D)
a. The power passing through any sphere around the source is
P=4π
l
If we ignore absoption of sound by the medium,
conservation of energy requires that
![r_{120} ^{2} I_{120} = r_{100}^{2} I_{100} =r_{10} ^{2} I_{10}](https://tex.z-dn.net/?f=r_%7B120%7D%20%5E%7B2%7D%20I_%7B120%7D%20%3D%20r_%7B100%7D%5E%7B2%7D%20%20I_%7B100%7D%20%3Dr_%7B10%7D%20%5E%7B2%7D%20I_%7B10%7D)
then,![r_{100} =r_{120} \sqrt{x} \frac{I_{120} }{I_{100} } =(3.00m)\sqrt{\frac{1\frac{W}{m^{2} } }{10^{-2}\frac{W}{m^{2} } } } =30 m](https://tex.z-dn.net/?f=r_%7B100%7D%20%3Dr_%7B120%7D%20%5Csqrt%7Bx%7D%20%5Cfrac%7BI_%7B120%7D%20%7D%7BI_%7B100%7D%20%7D%20%3D%283.00m%29%5Csqrt%7B%5Cfrac%7B1%5Cfrac%7BW%7D%7Bm%5E%7B2%7D%20%7D%20%7D%7B10%5E%7B-2%7D%5Cfrac%7BW%7D%7Bm%5E%7B2%7D%20%7D%20%20%7D%20%7D%20%3D30%20m)
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Answer:
A. I and V
Explanation:
According to Le Chatelier's Principle, increasing the product side will cause the equilibrium to shift back towards the reactant side, so I is true. By the same principle, II is false.
For gases, decreasing the pressure will cause the equilibrium to shift towards the side with higher number of moles. So V is true.
The reaction is endothermic, so increasing the temperature will shift the equilibrium to the products, so IV is false. And adding a catalyst has no effect on the equilibrium, so III is false.
A change in temperature can cause the a change in state of matter.
A physical change is where substance does not change where as in chemical reaction substance is changed and forms another form.