PROBLEMS
- What is the peak wavelength of light given off by the sun's photosphere which has a temperature of 5770K.
- What is the power emitted by the entire sun, if you assume it is a perfect black body? The diameter of the sun is . Assume the temperature is that of the photosphere, or 5770K.
- At what rate is heat lost due to evaporation by a hot tub that has a water temperature of 40 celsius and a surface area of 5.0 m2 if it sits outdoors in air of temperature 10 celsius and relative humidity of 20% with no wind blowing? How fast must the wind blow to double the rate of heat loss?
- A cylindrical plastic water bottle is filled with ice water on a day with air temperature of 30 C. The bottle is 25 cm tall and has a radius 4.0 cm. At what rate does it lose heat through all sides via conductivity if the thickness of the plastic is 3.0 mm? Assume the conductivity of the plastic is 0.20 W/m/K.
- To cook food like meat, it requires a certain amount of heat to be absorbed per unit mass of meat. Assume that it takes 3.0 hours to cook a thanksgiving turkey that has a weight of 10 lbs. How long should it take in the same oven to cook a 15 lb turkey?
- A rectangular prism shaped tank is filled with hot water and cools indoors to very nearly room temperature in 1.0 hrs. A second tank, with the same relative side lengths, made of the same material, and filled with water of the same temperature is placed in the same room, but takes 3.0 hrs to cool to very nearly room temperature. What is the ratio of water volume in the second tank to water in the first tank?
ANSWERS
1. 502nm
2. 3.81x1026W
3. 3910W; 1.32m/s
4. 146W
5. 3:26
6. 27