A 1-in diameter pure copper sphere is suspended in a room where the walls and air are all at 300K. The natural convection heat transfer coefficient around the sphere is 25 W/m both radiation and convection may be important. If the copper sphere is initially at 1000K, perform an energy balance on the sphere in order to write a differential equation describing the rate of change of temperature with time of the sphere. You do not need to solve the expression.