Does Heat Cause Area Expansion? Understanding the Expansion of Materials

AI Thread Summary
Heating an aluminum plate causes all dimensions, including the square hole, to expand due to thermal expansion. The formula δL/L = β*δT indicates that linear dimensions increase proportionally to temperature change. As the sides of the hole expand, the overall area of the hole increases rather than decreases. The confusion arises from misunderstanding that the expansion affects both the material surrounding the hole and the hole itself. Therefore, the correct conclusion is that the area of the hole becomes larger when the aluminum plate is heated.
hms.tech
Messages
246
Reaction score
0

Homework Statement



This is a question from my physics book, i don't understand its solution.

Consider a square hole in an aluminum plate (2D) . If this block is heated,
will this hole become smaller or larger ?

Homework Equations



δL/L = β*δT


The Attempt at a Solution



As each of the side of the block expands (some a lttle, while the longer sides more) thus the area decreases.

But, the answer as given by the book is that the area would increase.
Can anyone help me understand this ?
 
Physics news on Phys.org
All linear dimensions will expand by the same factor, including the hole.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...

Similar threads

Replies
6
Views
2K
Replies
5
Views
24K
Replies
4
Views
2K
Replies
2
Views
1K
Replies
11
Views
1K
Replies
5
Views
4K
Back
Top