Elastic force is the force exerted by an object that has been deformed when it tries to return to its original shape. This force is caused by the intermolecular forces between the particles of the object, which are trying to hold the object together in its original shape. When an object is deformed, the intermolecular forces are disrupted, and the object experiences an elastic force trying to restore it to its original shape.

The magnitude of the elastic force depends on the amount of deformation, the stiffness of the object, and the area over which the force is applied. The stiffness of an object is a measure of its resistance to deformation, and it depends on the intermolecular forces between the particles of the object. The area over which the force is applied is also important because a larger area means that the force is spread out over a greater number of particles, which reduces the magnitude of the force on each particle.

Elastic force is an important concept in many areas of physics, such as mechanics, materials science, and biophysics. It is used to explain a wide variety of phenomena, such as the stretching of rubber bands, the bending of beams, and the vibrations of strings.