Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] real-world problem and other questions about Car Talk



Now THAT'S more like it - ignoring the negative temperature coefficient
of the carbon brushes, of course! :-)

Brian W

On 2/5/2011 6:56 PM, Bob Sciamanda wrote:
?I think we want to say:

Delta R/R = 3.9E-3*DeltaT

=3.9E-3*50 = .2 = 20%

-----Original Message-----
From: brian whatcott
Sent: Saturday, February 05, 2011 4:53 PM
To: phys-l@carnot.physics.buffalo.edu
Subject: Re: [Phys-l] real-world problem and other questions about Car Talk



Nope. That's not right either! :-)

Brian W

On 2/5/2011 3:46 PM, brian whatcott wrote:
3.9E-3 DeltaR/DegC X 5E1 DegC = 2.0E-2 deltaR??

Brian W


On 2/5/2011 9:49 AM, Bernard Cleyet wrote:
I suspected not enuf change in resistance, but calc'd and find quite
reasonable. The starter on oldies is bolted to a frame, as part of the
engine case, so reasonable conductive path from the cylinders. So a 50 C
change is not unreasonable, which results in an ~ 20% change in Cu
resistivity.

[3.9 E-3 /C]
_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l
x