Q2:- Light from the sun arrives at the earth, an average of 1.48 x 101 m away, at the rate of 1.4 kW/m2 of area perpendicular to the direction of the light. Assume that sunlight is monochromatic with a frequency of 4.95 x 1014 Hz. (a) How many photons fall per second on each square meter of the earths surface directly facing the sun? (b) What is the power output of the sun, and how many photons per second does it emit?

Q2:- Light from the sun arrives at the earth, an average of 1.48 x 101 m away, at the rate of 1.4 kW/m2 of area perpendicular to the direction of the light. Assume that sunlight is monochromatic with a frequency of 4.95 x 1014 Hz. (a) How many photons fall per second on each square meter of the earths surface directly facing the sun? (b) What is the power output of the sun, and how many photons per second does it emit?

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.44P

See similar textbooks

Similar questions

1.26 Repeat Problem 1.25 but assume that the surface of the storage vessel has an absorbance (equal to the emittance) of 0.1. Then determine the rate of evaporation of the liquid oxygen in kilograms per second and pounds per hour, assuming that convection can be neglected. The heat of vaporization of oxygen at –183°C is .
The speed of sound in air is 340 m/s, and the speed of light is 3.0 X 108 m/s. What frequency oflight has the same wavelength as a 200.0 Hz sound wave?
At the surface of the sun, the temperature is approximately 5800 K. How much energy is contained in the electromagnetic radiation filling a cubic meter of space at the sun's surface?
A spherical radiator has a radius of 3ft and emissivity of 0.5. If radiates 6000 Btu/hr of heat at 3000R, what is the temperature of a surface affected by its radiation?
If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of
At midday when a black paved airport runway is directly under the Sun, it receives 800 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
6. Suppose that next week there is a news report that oxygen has been observedin the spectrum of an extra-solar planet. Would you believe it? What would this discoveryimply?
The speed of light is 186,000 miles per second and the sun, on average is 93 million miles from the earth. How long, in minutes, does it take for a photon of light to get from the sun to the earth?
The sun's intensity at the distance of the earth is 1370 W/m2W/m2. 30%% of this energy is reflected by water and clouds; 70%% is absorbed. What would be the earth's average temperature (in ∘C∘C) if the earth had no atmosphere? The emissivity of the surface is very close to 1. (The actual average temperature of the earth, about 15 ∘C∘C, is higher than your calculation because of the greenhouse effect.) Express your answer to two significant figures and include the appropriate units.
a) b) Assume that the solar receiver has cooled to 600 K at some point during the night. What is the value of its overall emissivity when it is at this new temperature? (Assume the original coating is still on the receiver) c) At this instance in time during the night (when Gs =0 and the solar receiver has cooled to 600 K), what is the rate of change of the temperature of the receiver with respect to time (dTr/dt ) in K/s if the amount of electricity being produced by the receiver does not change.
Definition radiation process in nanofluid and give some example
H4. Solar flux = 900 [w/m^2] h_air from glass cover = 25 [w/m^2-k] Emissivity_glass = 0.88 (nearly opaque to low frequency radiation Transmissivity of glass = 0.95 Alpha to incoming radiaiton = 0.9 T_ambient = 17 C Gap between plates = 25mm Bottom plate is insulated. Hr = radiation heat Hc = convective heat might need to use view factor FIND TEMPERATURE OF TOP SURFACE (the top is the glass) If anything is needed let me know i will try my best to update the question