Question 6
If atmospheric pressure is 103 360 Pa, what height of water column produces the same pressure? (density of water 1000 kg m−3; g = 10 m s−2)
The right answer is the one marked above.
10.336 m. From h ρ g = 103 360 we get h × 1000 × 10 = 103 360, so h = 103 360 ÷ 10 000 = 10.336 m.
A mercury column needs only 0.76 m — mercury is 13.6 times as dense as water, so water needs a column 13.6 times as tall for the same pressure.