1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Hunter-Best [27]
3 years ago
7

Imagine that the Earth had no atmosphere and was covered with a material that was a perfect thermal insulator (and zero thermal

inertia) that reflected 30 % of impinging sunlight back into space. The temperature of any point on the surface was determined by the power density of adsorbed sunlight being exactly matched by the power density radiated back into space (sT4 ), where s is the Stefan Boltzmann constant (5.67 x 10-8 W m-2 K-4 ) and T is the temperature in Kelvin. For a location on the equator, what would be the ground temperature (degrees K) at these four times; A) noon (sun overhead), B) at 3 pm (Sun 45 degrees from overhead), C) sunset and D) midnight.
Physics
1 answer:
Butoxors [25]3 years ago
5 0

Answer:

T_{12 \ pm} = 360 \ K

T_{3 \ pm} = 330 \ K

T = 131\ K

Explanation:

The power of sunlight at equator L_{sun} is known to be = 3.846*10^{26} \ W

Distance = 1 Au = 1.496*10^{11} \ m

Thus; the power at equator = \frac{3.846*10^{26}}{4 \pi *(1.496*10^{11})^2}

= 1367 W/m²

Now; at noon (sun overhead)

1367* \frac{70}{100}= 5.67*20^{-8}*T^4\\\\T^4 =\frac{956.9}{5.67*10^{-8}}\\\\T^4 = 1.687*10^{10}\\\\T_{12 \ pm} = 360 \ K

At 3 pm (Sun 45 degrees from overhead);

1367* \frac{70}{100}*cos \ 45 = 5.67*20^{-8}*T^4\\\\T^4 =\frac{676.63}{5.67*10^{-8}}\\\\T^4 = 1.193*10^{10}\\\\T_{3 \ pm} = 330 \ K

C) sunset and D) midnight.

We based our assumption on the notion that the incident angle at sunset and midnight be just below 90° ; for example . let say:

T_{6pm \  to \ 6 am} =  1367* \frac{70}{100}*cos 89 = \sigma T^4\\ \\T = 131\ K

You might be interested in
2 Which is true of a parallel circuit?
mars1129 [50]

Answer:

fxb

c

Explanation:bfffffffff

8 0
3 years ago
A car of m = 1200. kg collides with a tree while traveling 60.0 mph. The collision occurs over a time period of 0.0500 seconds.
MrRissso [65]
You may know linear momentum is given by P= mass.velocity. Initially car is moving with some velocity so you know initial momentum of the car. Finally it comes to rest i.e final momentum of the car is 0. According to Newton's second law : Force = change in momentum /time. Applying this you'll get answer as 642840N. Hope it helped you. Revert back to me if you have any questions. Please check out the calculation it might be wrong!
5 0
3 years ago
Read 2 more answers
What is the relationship between the applied force of a hanging mass on a spring and the spring force of the spring?
zaharov [31]

Answer:

elastic force and weight are related to the acceleration of the System.

Explanation:

The relationship between these two forces can be found with Newton's second law.

        F_{e} - W = m a

        K x - m g = m a

We see that elastic force and weight are related to the acceleration of the System.

If a harmonic movement is desired, an extra force that increases the elastic force is applied, but to begin the movement this force is eliminated, in general , if the relationship between this external and elastic force is desired, the only requirement is that it be small for harmonic movement to occur

7 0
3 years ago
A colloidal liquid in a has is called
S_A_V [24]
Aerosol is the answer
8 0
3 years ago
Gamma rays have more energy than X-rays. What else is true about gamma rays?
posledela
The answer is D. They have a higher frequency than X-rays.

Gamma-rays falls in the electromagnetic spectrum above, Gamma-rays have frequencies greater than 10¹⁸ cycles per second, or Hertz (Hz)
5 0
3 years ago
Other questions:
  • Which statement is not true?
    13·2 answers
  • WILL GIVE BRAINLIEST!!!
    15·2 answers
  • Question 11 of 11 | Page 11 of 11
    13·1 answer
  • A car is moving at 18 m/s when it accelerates at 8 m/s2 for 2 sec. What is his new velocity ?
    14·1 answer
  • It is easier to open the lid of a can using a spoon why?​
    14·2 answers
  • Which statements describe a physical property of matter? Check all that apply.
    12·1 answer
  • A digital stop-clock measures time in minutes and seconds.
    13·1 answer
  • En que consiste el atletismo de pista y campo?
    6·1 answer
  • A 10 kg-shopping cart is being pushed with a net force of 18 N, what is the acceleration
    13·1 answer
  • When is a secondary source more helpful than a primary source?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!