Radiation, temperature of earth, heat transfer

In summary, if an area of 1 m2 at the Earth surface emits Q/t = 54E-3 J/s in radiation, the temperature at the Earth surface would be 31.2 K if there were no other energy sources. This calculation assumes that the Earth is a perfect black body emitter with an emissivity of 1. However, the expected answer is 2.4 K, which may suggest that there is a mistake in the given Q/t value.
  • #1
bulbasaur88
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If an area of 1 m2 at the Earth surface emits Q/t = 54E-3 J/s in radiation, what would the temperature at the Earth surface be, if there would be no other energy sources? Assume that the Earth is a perfect black body emitter (e = 1).

Q/t = e(5.67E-8)(A)T4
54E-3 = 1(5.67E-8)T4
T = 31.2 K?

The answer is supposed to be 2.4 K? I feel pretty confident in my work so I am not certain where I have gone wrong.
 
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  • #2
Are you sure your Q/t is correct? The surface of the Earth is really -271 C?
 
  • #3
Given the numbers given in the problem statement, I agree with the 31.2 K value. It does sound silly to say this takes place somewhere on the Earth's surface though.
 

1. What is radiation?

Radiation is a form of energy that is emitted in the form of electromagnetic waves or particles. It can come from various sources, including the sun, electronic devices, or even radioactive materials.

2. How does radiation affect the temperature of Earth?

Radiation plays a crucial role in regulating the temperature of the Earth. The sun emits radiation, which is absorbed by the Earth's surface. This absorbed energy is then re-emitted as heat, which warms up the atmosphere and helps maintain the Earth's average temperature.

3. What is the greenhouse effect and how does it relate to temperature?

The greenhouse effect is a natural process where certain gases in the atmosphere trap heat and act as an insulating layer, keeping the Earth warm. Without this effect, the Earth's average temperature would be much colder. However, an increase in greenhouse gases due to human activity has led to an enhanced greenhouse effect, causing the Earth's temperature to rise.

4. How is heat transferred on Earth?

Heat can be transferred through three main mechanisms: conduction, convection, and radiation. Conduction is the transfer of heat through direct contact, while convection is the transfer of heat by the movement of fluids. Radiation is the transfer of heat through electromagnetic waves, and it does not require a medium for heat to be transferred.

5. What is the role of albedo in the temperature of Earth?

Albedo refers to the amount of sunlight that is reflected by a surface. Surfaces with high albedo, such as snow and ice, reflect more sunlight and have a cooling effect on the Earth. On the other hand, surfaces with low albedo, such as dark forests and oceans, absorb more sunlight and contribute to warming the Earth. Changes in albedo can have a significant impact on the Earth's temperature.

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