What is the formula for absolute pressure?

Absolute pressure is defined as the total pressure exerted by a fluid, taking into account both the atmospheric pressure and any additional pressure measured relative to it, known as gauge pressure. The concept helps in understanding how various pressures act in different conditions, especially in systems where pressure readings are crucial for operations.

In this context, atmospheric pressure is the pressure exerted by the weight of the atmosphere at a given point, and gauge pressure measures pressure above atmospheric pressure. Hence, to find the absolute pressure, you add the atmospheric pressure to the gauge pressure. This summation ensures that you capture the entire pressure experienced by a system, which is essential for calculations in engineering and safety assessments.

Other options provided do not accurately reflect the relationship between the types of pressure relevant to absolute pressure calculations. They may reference concepts related to mechanical systems but do not pertain to pressure measurement in the same manner.