A meteorite 1.20 cm in diameter is so hot immediately after penetrating the atmosphere that it radiates 20.0 kW of power. (a) What is its temperature, if the surroundings are at 20.0ºC and it has an emissivity of 0.800? (b) What is unreasonable about this result? (c) Which premise or assumption is responsible?

A meteorite 1.20 cm in diameter is so hot immediately after penetrating the atmosphere that it radiates 20.0 kW of power. (a) What is its temperature, if the surroundings are at 20.0ºC and it has an emissivity of 0.800? (b) What is unreasonable about this result? (c) Which premise or assumption is responsible?

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter1: Temperature And Heat

Section: Chapter Questions

Problem 119AP: For the human body, what is the rate of heat transfer by conduction through the body's tissue with...

See similar textbooks

Similar questions

For the human body, what is the rate of heat transfer by conduction through the body's tissue with the following conditions: the tissue thickness is 3.00 cm, the difference in temperature is 2.00 , and the skin area is 1.50 m2. How does this compare with the average heat transfer rate to the body resulting from an energy intake of about 2400 kcal per day? (No exercise is included.)
During a plant visit, it was observed that a 1.5-m-high and 1-m-wide section of the vertical front section of a natural gas furnace wall was too hot to touch. The temperature measurements on the surface revealed that the average temperature of the exposed hot surface was 110°C, while the temperature of the surrounding air was 25°C. The surface appeared to be oxidized, and its emissivity can be taken to be 0.7. Taking the temperature of the surrounding surfaces to be 25°C also, determine the rate of heat loss from this furnace. The furnace has an efficiency of 79 percent, and the plant pays $1.20 per therm of natural gas. If the plant operates 10 h a day, 310 days a year, and thus 3100 h a year, determine the annual cost of the heat loss from this vertical hot surface on the front section of the furnace wall.
How long does it take the Sun to melt a block of ice at 0∘C∘C with a flat horizontal area 1.0 m2m2 and thickness 1.5 cmcm ? Assume that the Sun's rays make an angle of 41 ∘∘ with the vertical and that the emissivity of ice is 0.050.
A sphere of radius 0.500 m, temperature 25.7o C, and emissivity 0.915 is isolated in an environment of temperature 77.0o C. At what rate does the sphere emit thermal radiation? At what rate does the sphere absorb thermal radiation? What is the sphere's net rate of energy exchange?
Consider a 260-m2 black roof on a night when the roof’s temperature is 27.5°C and the surrounding temperature is 12.5°C. The emissivity of the roof is 0.900. At what net rate does heat radiate, in kilowatts, from the roof?
A sphere of radius 0.50 m, temperature 27.0 °C, and emissivity 0.850 is located in an environment of temperature 77.0 °C. At what rate does the sphere emit thermal radiation? absorb thermal radiation? What is the sphere’s net rate of energy exchange?
Suppose that you intercept 5.0 * 10-3 of the energy radiated by a hot sphere that has a radius of 0.020 m, an emissivity of 0.80, and a surface temperature of 500 K. How much energy do you intercept in 2.0 min?
The temperature on Mars averages −47.2°C. What is that temperature in Fahrenheit, using TF = 9/5TC + 32°
At what net rate does heat radiate from a 326-m2 black roof on a night when the roof's temperature is 30.0°C and the surrounding temperature is 15.2°C? The emissivity of the roof is 0.900. *Answer in kW please
The skin temperature of a nude person is 34.0∘C and the surroundings are at 20.5∘C. The emissivity of skin is 0.905, and the surface area of the person is 1.55 m2. What is the rate P at which energy radiates from the person?
The outer surface of a spacecraft in space has an emissivity of 0.6 and an absorptivity of 0.2 for solar radiation. If solar radiation is incident on the spacecraft at a rate of 1000W/m2, determine the surface temperature of the spacecraft when the radiation emitted equals the solar energy absorbed.
A naked patient undergoes surgery in a warm room. Determine the ratio Pc /Pe, where Pc is the heat-power lost from the patient due to air convection and Pe is the heat-power lost from the patient due to evaporation. Take the skin temperature to be 32oC, the room temperature to be 29oC, the total body area to be 1.3 m2, the emissivity e = 1.0, and the convection of coefficient, q = 7.1 W/(m2.K). Take water to be lost from the patient by evaporation at a rate of 40 g/(m2.hr) and assume this to be pure water.