Question

The total surface energy of a liquid drop of radius 2 mm is 40 ergs. What is
the surface energy of a drop of the same liquid of radius 3 mm?​

Answer 1

Answer:

The total surface energy of a liquid drop of radius 2 mm is 40 ergs. What is

the surface energy of a drop of the same liquid of radius 3 mm?

Answer 2

Surface energy will be - 17.7 ergs

Surface energy is calculated by the formula - work/area.

Area of liquid drop if further calculated by the help of formula -

4πr².

In this formula, r represents radius.

Given values in question are -

R1 = 2 mm E1 = 40 ergs R2 = 3 mm

R1 is initial radius, E1 is initial surface energy, R2 is final radius and E2 has to be calculated.

According to formula given above -

E1R1² = E2R2²

E2 = E1R1²/R2²

E2 = 40*2²/3²

E2 = 17.7 ergs.

Thus, surface energy of liquid drop with increased radius will be 17.7 ergs.