Atmospheric Pressure Problem - Need Help.

In summary, the pressure at a point in a fluid increases with depth, and the deeper the point is placed, the greater the compression. To find the depth at which 100 cubic centimeters of water will enter a bottle filled with air, we need to consider the equal pressure at the level of the bottle opening, which is the sum of the atmospheric pressure and the hydrostatic pressure of water at that depth. Using Boyle's law, we can find the pressure of air inside the bottle and then use the hydrostatic equation to determine the necessary depth for the desired water volume.
  • #1
kriegera
74
0

Homework Statement



How does the pressure at a point in a fluid vary with the depth of the point below the surface of the fluid? A bottle, full of air at atmospheric pressure, whose volume is 500 cubic centimeters, is sunken mouth downwards below the surface of a pond. How far must it be sunk for 100 cubic centimeters of water to run up into the bottle?

Homework Equations





The Attempt at a Solution


I know that the deeper that point is placed in the fluid, the more pressure it experiences and the greater depth the bottle is lowered, the greater the compression. I know we're looking for the depth at which 100 cubic centimeters of air is replaced by 100 cubic centimeters of water but not sure how to proceed. Do I need to find the pressure of the bottle first? P=rgh but rearrange to find height/depth
H=P/rg ?
 
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  • #2
The pressure at the level of the bottle opening must be the same inside and outside.

Outside the bottle, the pressure is the sum of the atmospheric pressure Po and the hydrostatic pressure of water at depth h.
Inside the bottle, the pressure is the sum of the pressure of air, Pa, and the hydrostatic pressure of water column inside the bottle. You get the pressure or air in the bottle by using Boyle's law.

ehild
 
  • #3
ehild said:
The pressure at the level of the bottle opening must be the same inside and outside.

Outside the bottle, the pressure is the sum of the atmospheric pressure Po and the hydrostatic pressure of water at depth h.
Inside the bottle, the pressure is the sum of the pressure of air, Pa, and the hydrostatic pressure of water column inside the bottle. You get the pressure or air in the bottle by using Boyle's law.

ehild

Is there a hydrostatic equations for finding the pressure outside of the bottle?

we'll use Boyle's Law pV=k to solve for the inside but do we need to arrange: p=k/V?
Would we use the universal gas constant for this: 8.31432
So
p=500/8.31432 = 60.14 for inside pressure?
 

1. What is atmospheric pressure?

Atmospheric pressure is the force per unit area exerted by the weight of the Earth's atmosphere. It is caused by the gravitational pull of the Earth on the gas molecules in the atmosphere.

2. How is atmospheric pressure measured?

Atmospheric pressure is commonly measured using a barometer, which measures the height of a column of mercury or aneroid chamber that expands or contracts based on air pressure. The unit of measurement for atmospheric pressure is typically in millibars (mb) or inches of mercury (inHg).

3. What is standard atmospheric pressure?

Standard atmospheric pressure, also known as sea level pressure, is the average pressure at sea level. It is typically measured at 1013.25 millibars or 29.92 inches of mercury.

4. How does altitude affect atmospheric pressure?

As altitude increases, atmospheric pressure decreases because there is less weight of the atmosphere above. This means that at higher altitudes, there is less air pressure pushing down on an object.

5. What impact does atmospheric pressure have on weather?

Atmospheric pressure plays a crucial role in weather patterns. High pressure systems are associated with clear, sunny weather, while low pressure systems are associated with cloudy, rainy or stormy weather. Changes in atmospheric pressure can also indicate changes in weather conditions.

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