4.98 Pa is equivalent to approximately how many inches of water column?

4.98 Pa is equivalent to approximately how many inches of water column?

• A. 0.01 in
• B. 0.03 in
• C. 0.02 in
• D. 0.04 in

Answer: (C)

Converting small pressures between SI units and inches of water column is a common practical skill. Use the fact that 1 inch of water column (inH2O) is about 249 pascals (Pa). So for 4.98 Pa, the conversion is 4.98 Pa × (1 inH2O / 249 Pa) ≈ 0.02 inH2O. Therefore the pressure is about 0.02 inches of water column. To see why the other options don’t fit: 0.01 inH2O would correspond to roughly 2.49 Pa, 0.03 inH2O to about 7.47 Pa, and 0.04 inH2O to about 9.96 Pa—each not close to 4.98 Pa.

Converting small pressures between SI units and inches of water column is a common practical skill. Use the fact that 1 inch of water column (inH2O) is about 249 pascals (Pa).

So for 4.98 Pa, the conversion is 4.98 Pa × (1 inH2O / 249 Pa) ≈ 0.02 inH2O. Therefore the pressure is about 0.02 inches of water column.

To see why the other options don’t fit: 0.01 inH2O would correspond to roughly 2.49 Pa, 0.03 inH2O to about 7.47 Pa, and 0.04 inH2O to about 9.96 Pa—each not close to 4.98 Pa.