I thought about this power-temperature issue with the brakes before starting
this thread. I did not think about the scaling of brake surface area
seriously until D.Bowman's post. Was too caught up in the mass of the
brakes...
I tried to make some estimates. I still cannot make the numbers work.
I worked out that large (80,000 lb) truck has roughly 4 to 5 times the
braking surface area as a car - discussion with several of my students who
do repairs gave me the info. The truck needs to transfer 20 to 40 times more
KE than a car in stopping. Graphing some data from the web yields that truck
to car stopping distances are 1.8 on average.
This does not seem to add up. It would seem like a truck must have about 10
times the braking surface of a car to stop in 1.8 times the distance.
Where am I wrong?
Scott
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S.Goelzer
Physics Teacher
Coe - Brown Northwood Academy
Northwood NH 03261
603-942-5531 ext43
sgoelzer@coebrownacademy.com
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