On the basis of physical laws that require no assumption about kinds of optically induced forces and the quantity of these kind, we have shown that the momentum of light in matter is greater by n times than that of the same light in free space. Here n is the refractive index of the matter. If the momentum of a light pulse is considered, that it consists of two components. This is the electromagnetic one that is equal to 1/n2 part of the total momentum...