Which kind of intermolecular force attracts the stearate ion to the oil drop?

The intermolecular force attracts of the stearate ion in the oil drop.

Explanation:

Dispersion force is the intermolecular force that attracts the stearate ion to the oil drop. The weak force with temporary dipoles. This force is referred to as induced dipole attraction.The Dispersion is meant as an electron in two atoms occupies the position and this force is called induced dipole attraction.The Dispersion force depends on the atomic and molecular weight of the material.  

Distance^2= yellow line ^2 (see picture) = 30^2 + 49^2so distance = squareroot of (300^2 +49^2)i dont know if this is how to solve it, but i cnt think of another way