A student wants to lose some weight. He knows that rigorous aerobic activity uses about 700 kcal/h (2900 kJ/h) and that it takes about 2000 kcal per day (8400 kJ) just to support necessary biological functions, including keeping the body warm. He decides to burn calories faster simply by sitting naked in a 21° C room and letting his body radiate calories away. His body has a surface area of about 1.8 m2 and his skin temperature is 34.3° C. Assuming an emissivity of 1.0, at what rate will this student "burn" calories? in kcal/hr please show all work.