Question

Calculate (i) the pressure due to the weight of the water at a depth of 2.5 m and (ii) the depth below the surface of water at which the pressure due to the weight of the water equals 1.0 atm.

Answer 1

Data: h = 2.5 m, ρ = 1000 kg/m³, g = 9.8 m/s², 1 atm = 101.3 kPa

(i)  p = hρg = (2.5)(1000)(9.8)

= 2.45 ×10⁴ Pa

= `(2.45 xx 10^4)/(1.013 xx 10^5)` atm

= 0.2418 atm

This is the pressure at a depth of 2.5 m.

(ii) h = `p/(ρg)`

= `(1.013 xx 10^5)/((10^3)(9.8))`

= 10.34 m

This is the required depth.