A space probe is far away from the Sun, or any other sources of energy. It is kept warm (so the electronics work) by waste heat from a radioactive source. The radioactive source emits energy at a rate of 625W. The space probe can be modelled as a uniform sphere of metal. The radius is 1.3m, and the metal has a high thermal conductivity, so the probe is at a uniform temperature. The coefficient of linear expansion for this metal is 2.3 × 10-5 K-¹. 8. Suppose that the probe emits as a blackbody (with e = 1). What is the equilibrium temperature of the space probe? (a) 30K (b) 90K (c) ***150K (d) 240K (e) 320K 9. Suppose that the space probe is currently at temperature 200K, and it was launched from Earth at a temperature of 300K. By how much has the probe's volume decreased relative to the size at launch? (a) 2.1 x 10-2m³ (b) 4.2 × 10-2m³ (c) ***6.3 × 10-²m³ (d) 8.5 x 10-2m³ (e) There is not enough information to determine this.

A space probe is far away from the Sun, or any other sources of energy. It is kept warm (so the electronics work) by waste heat from a radioactive source. The radioactive source emits energy at a rate of 625W. The space probe can be modelled as a uniform sphere of metal. The radius is 1.3m, and the metal has a high thermal conductivity, so the probe is at a uniform temperature. The coefficient of linear expansion for this metal is 2.3 × 10-5 K-¹. 8. Suppose that the probe emits as a blackbody (with e = 1). What is the equilibrium temperature of the space probe? (a) 30K (b) 90K (c) 150K (d) 240K (e) 320K 9. Suppose that the space probe is currently at temperature 200K, and it was launched from Earth at a temperature of 300K. By how much has the probe's volume decreased relative to the size at launch? (a) 2.1 x 10-2m³ (b) 4.2 × 10-2m³ (c) 6.3 × 10-²m³ (d) 8.5 x 10-2m³ (e) There is not enough information to determine this.

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter14: Heat And Heat Transfer Methods

Section: Chapter Questions

Problem 62PE: The Sun radiates like a perfect black body with an emissivity of exactly 1. (a) Calculate the...

See similar textbooks

Similar questions

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?
The tungsten filament of an incandescent light bulb has a temperature of approximately 3000 K. The emissivity of tungsten is approximately 1/3, and you may assume that it is independent of wavelength. If the bulb gives off a total of 100 watts, what is the surface area of its filament in square millimeters?
The Sun has a diameter of approximately 1.4 x 109 m and a surface temperature of about 5650 C. Assuming that the Sun radiates as a blackbody with emissivity of unity, calculate the power radiated by the Sun into the solar system, which you can assume is at the temperature of the microwave background radiation.
Consider a surface at a uniform temperature of 800 K. Determine the maximum rate of thermal radiation that can be emitted by this surface, in W/m2.
The eye of a stove top has a total area of 0.0628 m2 and gives off energy at a rate of 8720 W. If we assume the stove top eye to be a perfect blackbody, what would be the temperature of the eye in Kelvin?
Consider steady heat transfer between two large parallel plates at constant temperatures of T1 = 290 K and T2 = 150 K that are L = 2 cm apart. Assuming the surfaces to be black (emissivity « = 1), determine the rate of heat transfer between the plates per unit surface area assuming the gap between the plates is (a) filled with atmospheric air, (b) evacuated, (c) filled with fiberglass insulation, and (d) filled with superinsulation having an apparent thermal conductivity of 0.00015 W/m·K.
Objects A and B have the same size and shape with emissivities eA and eB and temperatures TA and TB, respectively. (a) If eA = eB and TB = 4TA, what is the ratio PB /PA of their radiated powers? (b) If, instead, they radiate the same power and eA = 4eB, what is the ratio TB /TA of their Kelvin temperatures?
The radius of our sun is r = 6.96 × 108 m and its total power is 3.85 × 1026 W. The area of a sphere is A = 4πr2.a) Assuming that the surface of the Sun emits like a black body, calculate its surface temperatureb) Using the result of part (a), find λmax for the sun.
(b) A spherical surface of area 0.7m2, emissivity 0.88 and temperature 120°C is placed in a large, evacuated chamber whose walls are maintained at a fixed temperature. Find the rate at which radiation is emitted by the surface?( Stefan's constant o = 5.67 x 10-8 W/m²Tª ) Energy radiated per second in watts =
At midday when a large construction site covered with black tarps is directly under the Sun, it receives 975 W of solar power per square meter of surface from the Sun. If this hot surface loses energy only by radiation back into the atmosphere, what is its equilibrium temperature (in K)? You may use an emissivity of e = 1 for a black surface.
he rate at which radiant energy from the sun reaches the earth's upper atmosphere is about 1.50kW/m2. the distance from the earth to the sun is 1.50*1011 m, and the radius of the sun is 6.96x108 m. if the sun radiates as an ideal black body (e=1), what is the temperature of its surface?
Can we define the convection resistance for a unit surface area as the inverse of the convection heat transfer coefficient?