What is the absolute pressure if the gauge shows 350 kPa?

To determine the absolute pressure from the gauge pressure, it is essential to understand the relationship between gauge pressure and absolute pressure. Gauge pressure is the pressure measured relative to atmospheric pressure, meaning it does not take atmospheric pressure into account. Therefore, to find the absolute pressure, we must add the atmospheric pressure to the gauge pressure.

Typically, atmospheric pressure at sea level is approximately 101.3 kPa. If the gauge shows 350 kPa, you would calculate the absolute pressure as follows:

Absolute Pressure = Gauge Pressure + Atmospheric Pressure

Absolute Pressure = 350 kPa + 101.3 kPa

Absolute Pressure = 451.3 kPa

Rounding this result gives you an absolute pressure of around 451 kPa. This explains why option C is correct, as it closely matches the calculated absolute pressure after considering atmospheric pressure.