Question

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

Answer 1

Dear Student,

◆ Answer -

90 ergs

● Explanation -

We'll use CGS units here for convenience.

Surface energy of liquid drop is given by -

E = T × A

E = T × 4πr^2

40 = T × 4π × 0.2^2

40 = T × 4π × 0.04

T = 40 / 0.16π

T = 250/π J/sq.m

For 3 mm radius liquid drop is -

E = T × A

E = T × 4πr^2

E = 250/π × 4π × 0.3^2

E = 1000 × 0.09

E = 90 ergs

Hence, surface energy of 3 mm radius liquid drop is 90 ergs.

Thanks dear. Hope this helps you...

Answer 2

Answer:

◆ Answer -

90 ergs

● Explanation -

We'll use CGS units here for convenience.

Surface energy of liquid drop is given by -

E = T × A

E = T × 4πr^2

40 = T × 4π × 0.2^2

40 = T × 4π × 0.04

T = 40 / 0.16π

T = 250/π J/sq.m

For 3 mm radius liquid drop is -

E = T × A

E = T × 4πr^2

E = 250/π × 4π × 0.3^2

E = 1000 × 0.09

E = 90 ergs

Hence, surface energy of 3 mm radius liquid drop is 90 ergs.