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2 more thermal expansion questions

  • Thread starter F|234K
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  • #1
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1.) a steel rod is 3 cm in diameter at 25 C. a brass ring has an interior diameter of 2.992 cm at 25 C. at what common temperture will the ring just slide into the rod?

for this Q, i am not too sure which equation to use. i think it's the volume change one, which is delta V= beta(Vo)(delta T)

but i dont know how the temperature and the diameter is going to fit in...

2.) a grandfather's clock is calibrated at a temperature of 20 C. the pendulum is a think brass rod with a heavy mass attached to the end. on a hot day, when the temperature is 30 C, does the clock run fast or slow? how much time does it gain or lose in a 24 hour period?

this Q...i just have no idea how to start.....

thanks in advance, any suggestions/comments are greatly appreciated.
 

Answers and Replies

  • #2
Doc Al
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F|234K said:
1.) a steel rod is 3 cm in diameter at 25 C. a brass ring has an interior diameter of 2.992 cm at 25 C. at what common temperture will the ring just slide into the rod?

for this Q, i am not too sure which equation to use. i think it's the volume change one, which is delta V= beta(Vo)(delta T)

but i dont know how the temperature and the diameter is going to fit in...
Forget about volume; the rod will just slide into the ring when their diameters are the same. You need to find the [itex]\Delta T[/itex] that will have them end up with the same diameter.
2.) a grandfather's clock is calibrated at a temperature of 20 C. the pendulum is a think brass rod with a heavy mass attached to the end. on a hot day, when the temperature is 30 C, does the clock run fast or slow? how much time does it gain or lose in a 24 hour period?
Hint: How does the period of a pendulum depend on its length?
 
  • #3
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for number one, are u suggesting taht i should use the linear equation instead of the volume one?

linear equation being delta L=alpha(Lo)(delta T)
 
Last edited:
  • #4
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"Hint: How does the period of a pendulum depend on its length?"

taht the thing i dont no...so i cant do the Q....
 
  • #5
Doc Al
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44,871
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F|234K said:
for number one, are u suggesting taht i should use the linear equation instead of the volume one?
Absolutely.

Regarding the pendulum: Look it up! :smile:
 
  • #6
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thanks alot.
 

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