Q. A small block with a mass of 0.140 is attached to a cord passing through a hole in a frictionless, horizontal surface. The block is originally revolving at a distance of 0.50 from the hole with a speed of 0.90 . The cord is then pulled from below, shortening the radius of the circle in which the block revolves to 0.15 . At this new distance, the speed of the block is observed to be 3.00 .
What is the tension in the cord in the original situation when the block has speed = 0.90 ?
Q. A cube of ice is taken from the freezer at -9.3°C and placed in a 95 g aluminum calorimeter filled with 297 g of water at room temperature of 20°C. The final situation is observed to be all water at 15°C. What was the mass of the ice cube?