# Find the pressure exerted on the mercury?

• Jason03
In summary, the conversation discussed finding the atmospheric pressure at an altitude of 10km and using the height of a mercury column to determine the absolute pressure. There was also a question about how to incorporate the pressure acting on the mercury in the container. Jason03 suggested using the formula for gauge pressure at the bottom of the container, but also mentioned the specific value for gravity at 0 degrees latitude and 10km above sea level.

#### Jason03

I was working on a problem that stated an airplane is flying at an altitude of 10km. In its nonpressureized cargo bay is a container of mercury 325 mm deep.(the container is vented to the local atmosphere)

The first part just asked for the atmospheric pressure at 10km. Which I found in a table to be 26.5 kPa. But for the second part it asks to find the absolute pressure at 10km using the the 26.5 kPa and the height of the mercury column.

My question is how does the mercury column help you with finding the absolute pressure when the problem just says the mercry is sitting in a container? Do I just use ro*g*h to find the pressure exerted on the mercury? I would think there would need to be a height difference in the mercury because of the pressure acting on it.

It probably means, what is the absolute pressure at the very bottom of the mercury.

Jason03: I agree with the comment by Redbelly98. So you just need to figure out how one computes absolute pressure from gauge pressure, or vice versa. You listed the correct formula for gauge pressure at the bottom of the mercury container. However, did you know g at 0 deg latitude and 10 km above Earth sea level is g = 9.7495 m/s^2? I don't know if they want you to use that exact value or just the general constant.

## 1. What is the formula for finding the pressure exerted on mercury?

The formula for finding the pressure exerted on mercury is P = ρgh, where P is the pressure, ρ is the density of mercury, g is the acceleration due to gravity, and h is the height of the mercury column.

## 2. How do you measure the pressure of mercury?

The pressure of mercury is typically measured using a barometer, which is a device that measures atmospheric pressure by balancing the weight of a column of mercury against the pressure of the atmosphere.

## 3. What are the units of pressure used for measuring mercury?

The units of pressure used for measuring mercury are typically in units of atmospheres (atm) or millimeters of mercury (mmHg).

## 4. How does temperature affect the pressure exerted on mercury?

Temperature does not have a significant effect on the pressure exerted on mercury. However, as the temperature increases, the volume of mercury will expand and the height of the column will increase, resulting in a higher pressure reading.

## 5. What is the standard atmospheric pressure at sea level?

The standard atmospheric pressure at sea level is 1 atm or 760 mmHg. This is equivalent to 101.3 kilopascals (kPa) or 14.7 pounds per square inch (psi).