At a given place, a mercury barometer records a pressure of 0.70 m of Hg. What would be the height of water column if mercury in barometer is replaced by water ? Take density of mercury to be 13.6 x 10^3 kg m-3

ρ = 13.6 × 10³ kg m^-3

g = 9.8 m s ^-2

h = 0.70 m

Pressure = h ρ g

= 0.70 × 13.6 × 10³ × 9.8

= 93.3 × 10³ Pa

Now, if we use a water barometer,

P = 93.3 × 10³ Pa

ρ = 1 × 10³ kg m^-3

g = 9.8 m s ^-2

Pressure = h ρ g

93.3 × 10³ = h × 10³ × 9.8

h = 93.3 × 10³ / (10³ × 9.8) = 9.52 m

Hence, height of water colum = 9.52 m