Linear thermal expansion, a space between two metal rods

In summary, The brass bar and the aluminum bar, attached to an immovable wall, have a 1.33 x 10-3 m air gap between them at 21.8 °C. To determine the temperature at which the gap will be closed, the changes in length of the brass and aluminum bars must be considered. Using the initial temperature of 21.8 °C and the coefficients of thermal expansion for brass and aluminum, the final temperature is calculated to be approximately 49.31 °C.
  • #1
thatdudeuknow
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Problem: The brass bar and the aluminum bar are each attached to an immovable wall. At 21.8 °C the air gap between the rods is 1.33 x 10-3 m. At what temperature will the gap be closed? length of brass is 2.0 meters, aluminum is 1.o meters


Why my solution isn't working I'm not entirely sure, but I feel it may simply be errors in my calculus.



The attempt at a solution
aAlum= 23E-6 aBrass=19E-6

23E-6(1.0)chngT+19E-6(2.0)chngT=1.33E-3m
chngT(23E-6(1.0)+19E-6(2.0))=1.33E-3m
chngT=1.33E-3m/((23E-6(1.0)+19E-6(2.0))
chngT=20.78125
21.80+20.78125=42.58125C
 
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  • #2
Final Temperature : T
Initial Temperature : 21.8°C
Air gap between the rod/ Changes in Length of brass & aluminium bar: 1.33e-3m

Delta length of Brass + Delta length in Aluminium = 1.33e-3m
19e-6 x 2 x ( T-28) + 23e-6 x 1 x (T-28) = 1.33e-3m
6.1e-5T = 3.008e-3
T=49.31°C #
 

1. What is linear thermal expansion?

Linear thermal expansion is the tendency of a material, such as a metal rod, to expand or contract in length when exposed to changes in temperature.

2. How does linear thermal expansion occur?

When a material is heated, the atoms within the material vibrate faster and take up more space, causing the material to expand. When the material cools, the atoms slow down and the material contracts.

3. What is the space between two metal rods?

The space between two metal rods is the area where the two rods are not in direct contact with each other. This space can be affected by changes in temperature due to the expansion or contraction of the rods.

4. How is the space between two metal rods affected by temperature changes?

When the temperature increases, the metal rods will expand and the space between them will increase. When the temperature decreases, the rods will contract and the space between them will decrease.

5. Can the space between two metal rods be controlled?

The space between two metal rods can be controlled to some extent by using materials with different coefficients of thermal expansion. These materials will expand and contract at different rates, helping to minimize the change in the space between the rods due to temperature fluctuations.

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