1) What is the new angular speed?
2) Find the change in kinetic energy of the block.
3) How much work was done in pulling the cord? A small block on a frictionless, horizontal surface has a mass of 2.50x10-2kg .
It is attached to a massless cord passing through a hole in the surface (the figure ). The block is originally revolving at a distance of 0.300 m from the hole with an angular speed of 1.65rad/s . The cord is then pulled from below, shortening the radius of the circle in which the block revolves to 0.150 m. Model the block as a particle.
