Q1. A person eats a dessert that contains 220 Calories. (This "Calorie" unit, with a capital C, is the one used by nutritionists; 1 Calorie = 4186 J.) The skin temperature of this individual is 36°C and that of her environment is 27° C. The emissivity of her skin is 0.75 and its surface area is 1.3 m2. How much time would it take for her to emit a net radiant energy from her body that is like to the energy contained in this dessert?
Q2. A steel wire of length 1.97 with circular cross section must stretch no more than 0.260 when a tensile (stretching) force of 400 is applied to each end of the wire. What is the minimum diameter necessary? Assuming young's module for steel to be Y = 2.00e11Pa