[CBQ] Railroad Freight Cars Moving on Their Own

["Bob Weber" <eng95@comcast.net>]

I tried using this Davis formula for Railway Rolling Resistance, R(rolling 
resistance) = (1.3wn+29n) + bwnV + CAV² and from that computed the deceleration 
to get time and distance until it stops.
The accuracy of the results depends on the real rolling resistance and drag 
coefficients.  I used the following parameters in the equation and solved for 
the resistance in 10 second steps to get my answer.
Initial speed=50 mph, rolling res=0.045, drag=0.025, weight of car=30 tons and 
front area of car=90 ft² 
My spread sheet gives car travel 2.4 miles and takes 7.5 minutes to come to a 
stop.

Bob

[Non-text portions of this message have been removed]



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