Thermal coefficients of expansion

AI Thread Summary
The discussion revolves around calculating the temperature change required to close the gap between a brass rod and a copper sheet with a specific hole size. The initial equation presented for linear expansion is deemed incorrect, and the correct formula is suggested as L = L0(1 + αΔT). Participants express confusion regarding the formula and its components, particularly the meaning of L. Clarification is sought on how to apply the formula to determine the new dimensions of both the rod and the hole after a temperature change. Understanding thermal expansion concepts is emphasized as crucial for solving the problem.
Brian13
Messages
4
Reaction score
0

Homework Statement


A brass rod (linear expansion coef 19*10-6/°C) has a radius of 8139 cm and a copper (linear expansion coef 17*10-6/°C) sheet has a hole or radius 8139+8.86cm. What temperature change (K) is required to close the gap?

Homework Equations


ΔL/Lo = αΔT?

The Attempt at a Solution


I'm not even sure if the equation is right, so I'm really confused. Thanks for the help!
 
Physics news on Phys.org
Brian13 said:

Homework Statement


A brass rod (linear expansion coef 19*10-6/°C) has a radius of 8139 cm and a copper (linear expansion coef 17*10-6/°C) sheet has a hole or radius 8139+8.86cm. What temperature change (K) is required to close the gap?

Homework Equations


ΔL/Lo = αΔT?

The Attempt at a Solution


I'm not even sure if the equation is right, so I'm really confused. Thanks for the help!
That's some rod, if it has a diameter of over 16 meters!

Are you certain these are the dimensions for this problem?
 
I'm positive!
 
The equation is not correct. It should be:
$$L=L_0(1+\alpha \Delta T)$$So, if the temperature rises ΔT, in terms of #\Delta T#, what it the new radius of the rod? What is the new radius of the hole in the sheet?
 
I'm not entirely sure. I don't really understand the formula, so I'm having a hard time really wrapping my mind around it. I don't know what the L represents.
 
Brian13 said:
I'm not entirely sure. I don't really understand the formula, so I'm having a hard time really wrapping my mind around it. I don't know what the L represents.
Please say in words your understanding of the concept of thermal expansion.

Chet
 
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »
Thread 'Struggling to make relation between elastic force and height'

Thread 'Struggling to make relation between elastic force and height'

Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
View full post »

Similar threads

Thermal Expansion of a Wire Connected To a Rod
Replies
6
Views
3K
Thermal expansion of square from temperature increase of 50K
Replies
28
Views
2K
Problem concerning about thermal physics
Replies
3
Views
2K
Iron Ring Expansion: Solve for Δθ to Find Temp Increase
Replies
2
Views
2K
Volume expansion and sea level rise
Replies
6
Views
2K
Thermal Expansion: Volume vs. Linear - 0.11L Spilled
Replies
2
Views
2K
What is the Temperature at which the Gap Between Two Bars will be Closed?
Replies
4
Views
3K
Thermal expansion of bimetallic strip
Replies
19
Views
4K
Linear expansion of steel versus copper with increasing temperature
Replies
3
Views
2K
Thermal Expansion - Both rule and rod
Replies
2
Views
3K

Hot Threads

Recent Insights

Back
Top