Question

If water be used to construct a barometer, what would be the height of water-column at standard atmospheric pressure (76 cm of mercury)? '

Answer 1

The Pressure will be same whether the mercury is used or water is used, there is only a difference in density of liquid and height of Fluid.

For mercury, height is 76 cm.

∴ Pressure = hρg

= 76 × 13.6 × g

where 13.6 g/cm³ is the density of Mercury.

Now, let the height of the water column be h m.

∴ P = h × ρg, where density of water is 1 g/cm³.

∴ h × 1 = 76 × 13.6

⇒ h = 1033.6 cm.

∴ h = 10.336 m.

Hope it helps.