# How Can Sunrise Duration Estimate the Sun's Temperature?

• dimachka
In summary, the conversation is about a problem in thermodynamics class where the task is to estimate the temperature of the sun based on the information that sunrise lasts 2.1 minutes and assuming the Earth and sun are "black bodies". The student is confused and unsure how to approach the problem, but eventually manages to solve it and gets a close estimate of 5990 degrees Kelvin.
dimachka
So I've been given a problem in my thermodynamics class and it is completely confusing me. Here is the problem:

"Measured from the time when the first rays of sunshine appear above the horizon until the moment when the sun is fully visible, sunrise lasts 2.1 minutes. Based on this information, and assuming that the Earth and the sun are “black bodies”, can you estimate the temperature of the sun?"

Now I don't even have any clue what the teacher is getting at. I suppose that using that time i can estimate the velocity of the sun. I don't see how this will lead me towards an estimate of the sun's temperature since I can not assume the sun's kinetic energy is due to thermal energy. Can anyone give me a hint as to what i should even be thinking about? thanks.

"... can you estimate the temperature of the sun?"

Looks like a "yes/no" to me --- which is it?

:-) somehow I don't think a simple no I can't will suffice, haha. Wikipedia has a nifty way of estimating the temperature of the sun just using the distance between the sun and earth, and the radius of the sun, however I'm not sure how I can get both of these values simply from know this 2.1 minute value. Anyone got a hint for me?

Well I've managed to answer the question, and i get an estimate of 5990 degrees kelvin which doesn't seem far off at all. I'm pleased. If anyone is interested in what I did, post here and i'll post my solution.

## 1. What is thermodynamics?

Thermodynamics is the branch of physics that deals with the relationships between heat, work, energy, and other forms of energy.

## 2. What are the three laws of thermodynamics?

The first law states that energy cannot be created or destroyed, only transformed from one form to another. The second law states that the total entropy of a closed system will always increase over time. The third law states that the entropy of a perfect crystal at absolute zero temperature is zero.

## 3. How does thermodynamics relate to everyday life?

Thermodynamics plays a crucial role in many aspects of our everyday lives, such as the functioning of engines and refrigerators, the production of electricity, and the cooking of food.

## 4. What are some real-world applications of thermodynamics?

Some real-world applications of thermodynamics include power generation, chemical reactions, and climate control systems.

## 5. How can I improve my understanding of thermodynamics?

To improve your understanding of thermodynamics, it is important to read and study the fundamental principles, practice solving problems, and seek out real-world examples and applications. You can also attend lectures or workshops and discuss concepts with other scientists or experts in the field.

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