Question

A raindrop of diameter 4 mm is about to fall on the ground. Calculate the pressure inside the raindrop. [Surface tension of water T = 0.072 N/m, atmospheric pressure = 1.013 x 10⁵ N/m² ]

Answer 1

Given:

T = 0.072 N/m,

d = 4mm ∴ r = 2 * 10^-3 m,

P_o = 1.013 * 10⁵ N/m²

To find: Pressure inside the raindrop (P_i)

Formula: Pi = Po + 2T/r

Calculation: From formula,

`P_i=1.013xx10^5+(2xx0.072)/(2xx10^(-3))`

`P_i=1.013xx10^5+0.072xx10^3`

    `=1.013xx10^5+0.00072xx10^5`

`thereforeP_i=1.01372xx10^5Pa`

The pressure inside the raindrop is 1.01372 * 10⁵ Pa.