Two droplets coalesce in a single drop in this process
Answers
Explanation:
Two individual liquid drops have a greater surface area than that of a single drop formed after their coalescence. So, coalescencereduces the surface area. ... Since final energy(after coalescence) is less than the initial energy, energy must be released in the process.
answer : option (a) energy is liberated
your question -> Two droplets coalesce in a single drop. In this process
(a) energy is liberated
(b) energy is absorbed
(c) energy does not change
(d) some mass is converted into energy
answer : let radius of each droplet is r. after coalition, radius of bigger drop is R.
then, 2 × volume of droplets = volume of drop
⇒2 × 4/3 πr³ = 4/3 πR³
⇒R = (2)⅓ r
now, change in area = final area - initial area
= 4πR² - 2 × 4πr²
= 4π{(2)⅔r² - 2r²} < 0
so, energy change = Surface tension × change in area < 0
change in energy is negative it means, final energy is less than initial energy. it shows some amount of energy is released in coalition and hence option (a) is correct choice.