Final answer:
To find the pressure difference between two pipes using a double-fluid manometer, use the formula Δp = pb - pa, where h is the height difference between the manometer fluid columns, p is the density of the manometer fluid, and g is the acceleration due to gravity. The density of the oil and its column height may also be considered if relevant.
Step-by-step explanation:
To do this, one must understand that a manometer measures pressure differences by the height of the fluid column in the U-shaped tube. If the pressure in the oil pipe (pb) is greater than the pressure in the water pipe (pa), the fluid in the manometer on the side of the oil pipe will be lower than the fluid on the side of the water pipe, and vice versa. According to the given information, the gauge pressure Pg can be calculated using Pg = hpg, where h is the height difference between the fluid levels in the manometer, p is the density of the fluid used in the manometer (– in this case, we might assume it is mercury or another manometer fluid), and g is the acceleration due to gravity. Atmospheric pressure cancels out when measuring with a manometer, as it affects both sides of the manometer equally. Realizing this, we could calculate the pressure difference Δp by taking into account the density of the manometer fluid and the observed height difference h between the two columns of liquid.