Answer :
To find the absolute pressure of a gas when the gauge pressure is given, you need to understand the relationship between gauge pressure and absolute pressure.
1. Gauge Pressure: This is the pressure measured by a gauge, which doesn't take into account the atmospheric pressure. It's the pressure above atmospheric pressure.
2. Atmospheric Pressure: This is the pressure exerted by the Earth's atmosphere. On average, it's about 101 kPa, but for problems like this, it is often approximated as 100 kPa for simplicity.
3. Absolute Pressure: This is the total pressure, including both the gauge pressure and the atmospheric pressure. The formula for absolute pressure is:
[tex]\[
\text{Absolute Pressure} = \text{Gauge Pressure} + \text{Atmospheric Pressure}
\][/tex]
Given in the problem:
- Gauge pressure = 156 kPa
- Atmospheric pressure ≈ 100 kPa
Using the formula, add the gauge pressure to the atmospheric pressure:
[tex]\[
\text{Absolute Pressure} = 156\, \text{kPa} + 100\, \text{kPa} = 256\, \text{kPa}
\][/tex]
So, the absolute pressure is approximately 256 kPa.
Therefore, the correct option is D) 256 kPa.
1. Gauge Pressure: This is the pressure measured by a gauge, which doesn't take into account the atmospheric pressure. It's the pressure above atmospheric pressure.
2. Atmospheric Pressure: This is the pressure exerted by the Earth's atmosphere. On average, it's about 101 kPa, but for problems like this, it is often approximated as 100 kPa for simplicity.
3. Absolute Pressure: This is the total pressure, including both the gauge pressure and the atmospheric pressure. The formula for absolute pressure is:
[tex]\[
\text{Absolute Pressure} = \text{Gauge Pressure} + \text{Atmospheric Pressure}
\][/tex]
Given in the problem:
- Gauge pressure = 156 kPa
- Atmospheric pressure ≈ 100 kPa
Using the formula, add the gauge pressure to the atmospheric pressure:
[tex]\[
\text{Absolute Pressure} = 156\, \text{kPa} + 100\, \text{kPa} = 256\, \text{kPa}
\][/tex]
So, the absolute pressure is approximately 256 kPa.
Therefore, the correct option is D) 256 kPa.
