Select The Best Answer For The Question.What Is The Absolute Pressure If The Gauge Pressure Of A Gas Is 114 KPa?A. 50 KPa B. 220 KPa C. 214 KPa D. 14 KPa

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Introduction

In the field of physics, particularly in the study of fluids and gases, it is essential to understand the concepts of absolute pressure and gauge pressure. Absolute pressure is the total pressure exerted by a gas on a surface, while gauge pressure is the pressure measured relative to atmospheric pressure. In this article, we will explore the relationship between absolute pressure and gauge pressure, and use a practical example to determine the absolute pressure of a gas given its gauge pressure.

What is Absolute Pressure?

Absolute pressure is the total pressure exerted by a gas on a surface, measured in units of pascals (Pa) or kilopascals (kPa). It is the sum of the gauge pressure and the atmospheric pressure. Atmospheric pressure is the pressure exerted by the weight of the air in the atmosphere, and it is typically around 101.3 kPa at sea level.

What is Gauge Pressure?

Gauge pressure, on the other hand, is the pressure measured relative to atmospheric pressure. It is the pressure exerted by a gas on a surface, measured in units of pascals (Pa) or kilopascals (kPa), without considering the atmospheric pressure. Gauge pressure is often used in everyday applications, such as measuring the pressure of a tire or a gas cylinder.

Relationship between Absolute Pressure and Gauge Pressure

The relationship between absolute pressure and gauge pressure is given by the following equation:

Absolute Pressure (P_abs) = Gauge Pressure (P_gauge) + Atmospheric Pressure (P_atm)

where P_abs is the absolute pressure, P_gauge is the gauge pressure, and P_atm is the atmospheric pressure.

Example: Determining Absolute Pressure from Gauge Pressure

Let's consider an example where we are given the gauge pressure of a gas as 114 kPa, and we need to determine the absolute pressure. We know that the atmospheric pressure is 101.3 kPa. Using the equation above, we can calculate the absolute pressure as follows:

P_abs = P_gauge + P_atm = 114 kPa + 101.3 kPa = 215.3 kPa

Therefore, the absolute pressure of the gas is 215.3 kPa.

Selecting the Best Answer

Now that we have calculated the absolute pressure of the gas, let's look at the options provided:

A. 50 kPa B. 220 kPa C. 214 kPa D. 14 kPa

Based on our calculation, the absolute pressure of the gas is 215.3 kPa, which is closest to option C. 214 kPa.

Conclusion

In conclusion, understanding the relationship between absolute pressure and gauge pressure is crucial in various applications, such as engineering, physics, and chemistry. By using the equation P_abs = P_gauge + P_atm, we can easily determine the absolute pressure of a gas given its gauge pressure. In this article, we used a practical example to demonstrate this concept and selected the best answer from the options provided.

Key Takeaways

  • Absolute pressure is the total pressure exerted by a gas on a surface, measured in units of pascals (Pa) or kilopascals (kPa).
  • Gauge pressure is the pressure measured relative to atmospheric pressure, measured in units of pascals (Pa) or kilopascals (kPa).
  • The relationship between absolute pressure and gauge pressure is given by the equation P_abs = P_gauge + P_atm.
  • Atmospheric pressure is the pressure exerted by the weight of the air in the atmosphere, and it is typically around 101.3 kPa at sea level.

References

Additional Resources

Introduction

In our previous article, we explored the concepts of absolute pressure and gauge pressure, and used a practical example to determine the absolute pressure of a gas given its gauge pressure. In this article, we will answer some frequently asked questions (FAQs) related to absolute pressure and gauge pressure.

Q: What is the difference between absolute pressure and gauge pressure?

A: Absolute pressure is the total pressure exerted by a gas on a surface, measured in units of pascals (Pa) or kilopascals (kPa). Gauge pressure, on the other hand, is the pressure measured relative to atmospheric pressure, measured in units of pascals (Pa) or kilopascals (kPa).

Q: How do I convert gauge pressure to absolute pressure?

A: To convert gauge pressure to absolute pressure, you need to add the atmospheric pressure to the gauge pressure. The formula is:

Absolute Pressure (P_abs) = Gauge Pressure (P_gauge) + Atmospheric Pressure (P_atm)

Q: What is the atmospheric pressure?

A: Atmospheric pressure is the pressure exerted by the weight of the air in the atmosphere, and it is typically around 101.3 kPa at sea level.

Q: Can I use gauge pressure to measure the pressure of a gas in a container?

A: Yes, you can use gauge pressure to measure the pressure of a gas in a container, but you need to make sure that the container is sealed and there is no air leakage. If there is air leakage, the gauge pressure will not accurately represent the pressure of the gas.

Q: How do I measure absolute pressure?

A: To measure absolute pressure, you need to use a pressure gauge that is calibrated to measure absolute pressure. You can also use a pressure transducer or a pressure sensor to measure absolute pressure.

Q: Can I use a pressure gauge to measure both gauge pressure and absolute pressure?

A: Yes, you can use a pressure gauge to measure both gauge pressure and absolute pressure, but you need to make sure that the gauge is calibrated to measure both types of pressure. Some pressure gauges have a switch or a button that allows you to switch between gauge pressure and absolute pressure.

Q: What are some common applications of absolute pressure and gauge pressure?

A: Absolute pressure and gauge pressure are used in various applications, such as:

  • Engineering: to design and build pressure vessels, pipelines, and other equipment
  • Physics: to study the behavior of gases and fluids
  • Chemistry: to study the properties of gases and liquids
  • Medicine: to measure blood pressure and other physiological pressures
  • Aerospace: to measure the pressure of gases and liquids in aircraft and spacecraft

Q: Can I use absolute pressure and gauge pressure in everyday life?

A: Yes, you can use absolute pressure and gauge pressure in everyday life, such as:

  • Measuring the pressure of a tire or a gas cylinder
  • Checking the pressure of a water tank or a swimming pool
  • Measuring the pressure of a gas stove or a gas oven
  • Checking the pressure of a car's brake system or a hydraulic system

Conclusion

In conclusion, absolute pressure and gauge pressure are two important concepts in physics and engineering. Understanding the difference between them and how to convert between them is crucial in various applications. We hope that this Q&A article has helped to clarify any doubts you may have had about absolute pressure and gauge pressure.

Key Takeaways

  • Absolute pressure is the total pressure exerted by a gas on a surface, measured in units of pascals (Pa) or kilopascals (kPa).
  • Gauge pressure is the pressure measured relative to atmospheric pressure, measured in units of pascals (Pa) or kilopascals (kPa).
  • The relationship between absolute pressure and gauge pressure is given by the equation P_abs = P_gauge + P_atm.
  • Atmospheric pressure is the pressure exerted by the weight of the air in the atmosphere, and it is typically around 101.3 kPa at sea level.

References

Additional Resources