Acopper cylinder of diameter 30 cm and 30 cm length has an internal generation at a rate of 1.5 × 106 w/m^3. the cylinder is placed inside a large chamber. the air around the cylinder and the chamber walls are at a temperature of 20°c. the cylinder is losing heat to the surroundings through convection and radiation. the convection heat transfer coefficient is 200 w/m^2-k. at an instant of time t, the surface temperature of the cylinder is 400°c. determine the rate of temperature change of the body at that instant in °c/s. assume emissivity of copper is 0.2