If a reading from a 20-point traverse shows a velocity pressure (VP) of .48" wg, what would the velocity of the air be?

To determine the velocity of the air from the velocity pressure (VP) measurement of 0.48 inches of water gauge (wg), we can use the formula for air velocity derived from velocity pressure:

[ V = 4005 \times \sqrt{VP} ]

In this scenario, the velocity pressure is given as 0.48" wg. Plugging this value into the formula:

[ V = 4005 \times \sqrt{0.48} ]

Calculating the square root of 0.48 gives approximately 0.692. Therefore, the calculation for the air velocity becomes:

[ V = 4005 \times 0.692 \approx 2775 \text{ feet per minute (fpm)} ]

This is consistent with the correct answer choice, confirming that the calculation correctly reflects the relationship between velocity pressure and air velocity. The specific value of 2775 fpm is derived accurately from the defined formula, thus justifying its selection as the right answer in this context.