# Need some direction please. Thermodynamics.

• travism123
In summary, the conversation discusses the problem of determining the temperature at which an aluminum wing would be 0.05m shorter. The equation used to solve this problem is ∆T = ∆l / α x l, where ∆T is the temperature difference, ∆l is the change in length, α is the coefficient of linear expansion, and l is the initial length. After some trial and error, the correct temperature is found to be -46.667*C. The conversation also mentions the difficulties and doubts of the person asking the question due to their lack of expertise in physics.
travism123

## Homework Statement

Aluminum wing is 30m long at 20*c

At what temperature would the wing be .05m shorter?

The coefficient for linear expansion of aluminum is (16 x 10^-6/c)

I have no idea how to do this. I don't want an answer. Just an equation or a hint on what to do. Thank you very much.

What is the relation between the initial length , final length , coefficient of linear expansion and temperature difference?

I have no idea.

Where did you get that coefficient? "16 x 10^-6/c" Are you sure of the "units"? What does "/c" mean? You might want to check that.

Sorry,
I messed up the coefficient. It's 25 x 10^-6/*C

I'm sorry if I sound stupid not being able to figure this question out. The truth is I probably have no business being in a physics class. I'm going to school to be a therapist and am taking this class to fill a science requirement. I'm sure there are easier classes I could've taken, but a few months before the semester started I saw that documentary The Elegant Universe and thought hmm... physics looks fun. That blasted Brian Greene and his easy to understand explanations!

Does this look right?

Aluminum wing is 30m at 20*C. At what temp would it be .05m shorter.
∆T = ∆l / α x l
∆T = -.05m/(25 x 10-6/*C) x 30m
∆T = -66.667
The wing would be at -46.667*C to be .05m shorter.

Yes.

Thank you very much.

## 1. What is thermodynamics?

Thermodynamics is the branch of physics that deals with the study of energy and its transformations, particularly in relation to heat and work.

## 2. Why is thermodynamics important?

Thermodynamics is important because it helps us understand how energy is transferred and transformed in different systems, and how these processes can be controlled and optimized for practical applications.

## 3. What are the laws of thermodynamics?

The laws of thermodynamics are fundamental principles that govern energy and its interactions. They include the first law, which states that energy cannot be created or destroyed, only transformed, and the second law, which states that the total entropy of a closed system will always increase over time.

## 4. How is thermodynamics applied in real life?

Thermodynamics has many practical applications, including in the design of engines and power plants, refrigeration and air conditioning systems, and chemical reactions. It is also used in fields such as meteorology, geology, and biology.

## 5. What are some common misconceptions about thermodynamics?

One common misconception is that thermodynamics only applies to high-temperature systems, when in fact it is relevant to all energy interactions. Another misconception is that the second law of thermodynamics contradicts the idea of evolution, when in reality it only applies to closed systems and living organisms are open systems.

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