A small block on a frictionless horizontal surface has a mass of $0\mathrm{.}0250$kg$.$ It is attached to a massless cord passing through a hole in the surface. the block is originally revolving at a distanve of $0\mathrm{.}300$ m from the hole with an angular speed of $1\mathrm{.}75$ rad$/$s$.$ The cord is then pulled from below, shortening the radius of the circle in which the block revolves to $0\mathrm{.}150$m$.$ You may treat the block as a particle. Is the angular moment conserved? What is the new angular speed? Find the change in kinetic energy of the block. How much work is done in pulling the cord?