Explanation:
It is known that wave intensity is the power to area ratio.
Mathematically, I = 
As it is given that power is 28.0 W and area is
.
Therefore, sound intensity will be calculated as follows.
I = 
= 
= 
or, = 
Thus, we can conclude that sound intensity at the position of the microphone is
.
Answer:
2.68 hours
Explanation:
A.) Suppose the wind blows out from the west (with the air moving east). The pilot should then head her plane to northwest direction to move directly north.
B.) Given that plane flies at a speed of 102 km/h in still air. And the wind blows out from the west (with the air moving east) at a speed of 46 km/h.
The plan resultant speed can be calculated by using pythagorean theorem.
Resultant Speed = Sqrt( 102^2 + 46^2 )
Resultant Speed = Sqrt( 12520)
Resultant speed = 111.89 km/h
From the definition of speed,
Speed = distance/time
Where distance = 300 km
Substitute the resultant speed and the distance into the formula.
111.89 = 300/time
Time = 300/111.89
Time = 2.68 hours
Therefore, it take her 2.68 hours to reach a point 300 km directly north of her srarting point
Answer:
The number of oxygen molecules in the left container greater than the number of hydrogen molecules in the right container.
Explanation:
Given:
Molar mass of oxygen, 
Molar mass of hydrogen, 
We know ideal gas law as:

where:
P = pressure of the gas
V = volume of the gas
n= no. of moles of the gas molecules
R = universal gs constant
T = temperature of the gas
∵
where:
m = mass of gas in grams
M = molecular mass of the gas
∴Eq. (1) can be written as:


as: 
So,

Now, according to given we have T,P,R same for both the gases.




∴The molecules of oxygen are more densely packed than the molecules of hydrogen in the same volume at the same temperature and pressure. So, <em>the number of oxygen molecules in the left container greater than the number of hydrogen molecules in the right container.</em>
<span>It takes heat to make something evaporate, so it takes heat from your arm. Alcohol easily evaporates at room temperature, so it feels cool. This is also why you feel cool when getting out of the pool. The water on your skin evaporates.
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