What tendency do molecules on the surface of a liquid possess?

Why are clothes easily washed by soap or detergent?

The length of a needle floating on the surface of water is $1.5\,cm$. The force in addition to its weight required to lift the needle from the water surface will be...... $N$ (surface tension of water $= 7.5\,N/cm$).

It is easier to spray water to which soap is added because the addition of soap to water:

$n$ number of liquid drops each of radius $r$ coalesce to form a single drop of radius $R$. The energy released in the process is converted into the kinetic energy of the big drop so formed. The speed of the big drop is [$T = \text{surface tension of liquid}, \rho = \text{density of liquid}$.]

Soap helps in cleaning clothes,because