Thermal expansion and rotation ( 4 points ) Learning Objectives: Connecting concepts of thermal expansion and rotational motion A solid brass sphere rotates freely around an axis going through its center. When its temperature changes by 300 C - what is the ratio of its rotational frequencies at low and high temperature? [ use coefficient of linear expansion of brass of 2.00 . 10-5 1/K, look up moment of inertia if needed ]Specific Heat ( 4 points ) Learning Objectives: Apply the concept of specific heat to calculate temperature changes. A 90.0 g copper sphere is heated by a flame so that it reaches the temperature of the flame. After that the sphere is put in a container filled with 210 g water at a temperature of 10.0 .C. The sphere cools down and heats the water to 35.0 .C. What temperature had the flame? Neglect the heat capacity of the container. [ use heat capacity of Cu: 0.383 kJ/(kg K), heat capacity water: 4.19 kJ/(kg K)