A small block on a frictionless horizontal surface has a mass of2.50×10-2kg. It is attached to a masslesscord passing through a hole in the surface. The block is originallyrevolving at a distance of 0.300m from the hole with an angularspeed of 1.75rad/s. The cord is then pulled from below, shorteningthe radius of the circle in which the block revolves to 0.150m. Youmay treat the block as a particle.
What is the new angular speed?
Find the change in kinetic energy of the block.
How much work was done in pulling the cord?