Q. A small block with a mass of 0.170 kg is attached to a cord passing through the hole in a frictionless, horizontal surface .The block is initially revolving at a distance of 0.50 m from the hole with a speed of 0.80 m/s. The cord is then pulled from below, shortening the radius of the circle in which the block revolves to 0.1 m. At this new distance, speed of the block is observed to be 3.60 m/s.
What is the tension in the cord in the original situation when block has speed v_0 = 0.90 m/s?
What is the tension in the cord in the final situation when block has speed v_1 = 3.00 m/s?
How much work was completed by the person who pulled on the cord?