The whole definition of frequency is: <em>How often something happens. </em>
Especially referring to something that happens over and over and over and over.
One example is Choice-C: How often the particles of a medium vibrate.
"Frequency" comes from the word "frequent". That means "often", and "frequency" just means "often-ness" ... HOW often the thing happens.
Some other examples:
Frequency of jump-roping . . . maybe 60 per minute .
Frequency of rain . . . maybe 5 per month .
Frequency of an AM radio station . . . maybe 1 million waves per second.
(If it's something <u><em>per second</em></u>, then we call it "Hertz". That's not for the car rental company. It's for Heinrich Hertz, the German Physicist who was the first one to prove that electromagnetic waves exist. He sent radio waves all the way ACROSS HIS LABORATORY and detected them at the other side ( ! ), in 1887.)
Frequency of the wiggles in the sound wave coming out of a trumpet playing the note ' A ' . . . 440 Hertz.
Frequency of sunrise and the Chicago Tribune newspaper . . . 1 per day
Frequency of the cycle of Moon phases and an average human woman's ovulation cycle: 1 per 29.531 days, 1 per ~28 days .
Answer:
O a force that opposes motion
Answer:
The speed of the water flow in the pipe on the second floor is approximately 13.1 meters per second.
Explanation:
By assuming that fluid is incompressible and there are no heat and work interaction through the line of current corresponding to the pipe, we can calculate the speed of the water floor in the pipe on the second floor by Bernoulli's Principle, whose model is:
(1)
Where:
,
- Pressures of the water on the first and second floors, measured in pascals.
- Density of water, measured in kilograms per cubic meter.
,
- Speed of the water on the first and second floors, measured in meters per second.
,
- Heights of the water on the first and second floors, measured in meters.
Now we clear the final speed of the water flow:
![\frac{\rho\cdot v_{2}^{2}}{2} = P_{1}-P_{2}+\rho \cdot \left[\frac{v_{1}^{2}}{2}+g\cdot (z_{1}-z_{2}) \right]](https://tex.z-dn.net/?f=%5Cfrac%7B%5Crho%5Ccdot%20v_%7B2%7D%5E%7B2%7D%7D%7B2%7D%20%3D%20P_%7B1%7D-P_%7B2%7D%2B%5Crho%20%5Ccdot%20%5Cleft%5B%5Cfrac%7Bv_%7B1%7D%5E%7B2%7D%7D%7B2%7D%2Bg%5Ccdot%20%28z_%7B1%7D-z_%7B2%7D%29%20%5Cright%5D)
![\rho\cdot v_{2}^{2} = 2\cdot (P_{1}-P_{2})+\rho\cdot [v_{1}^{2}+2\cdot g\cdot (z_{1}-z_{2})]](https://tex.z-dn.net/?f=%5Crho%5Ccdot%20v_%7B2%7D%5E%7B2%7D%20%3D%202%5Ccdot%20%28P_%7B1%7D-P_%7B2%7D%29%2B%5Crho%5Ccdot%20%5Bv_%7B1%7D%5E%7B2%7D%2B2%5Ccdot%20g%5Ccdot%20%28z_%7B1%7D-z_%7B2%7D%29%5D)

(2)
If we know that
,
,
,
and
, then the speed of the water flow in the pipe on the second floor is:


The speed of the water flow in the pipe on the second floor is approximately 13.1 meters per second.
Answer:
Equilibrium temperature will be 
Explanation:
We have given weight of the lead m = 2.61 gram
Let the final temperature is T
Specific heat of the lead c = 0.128
Initial temperature of the lead = 11°C
So heat gain by the lead = 2.61×0.128×(T-11°C)
Mass of the water m = 7.67 gram
Specific heat = 4.184
Temperature of the water = 52.6°C
So heat lost by water = 7.67×4.184×(T-52.6)
We know that heat lost = heat gained
So 


Answer:
I think the answer is A
Explanation:
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