Old 25th Nov 2012, 22:18
  #111 (permalink)  
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 76
Posts: 1,331
Originally Posted by HazelNuts39
If you loaded both trains to have the same mass, would they decelerate at the same rate?
As usual, you've raised a very valid point.

Well, I took both locos/engines and tried the experiment again with just them. One was Thomas and the other was Billy, with identical wheel base / bearings etc.., and yet Thomas came to a stop earlier. So, I got out some scales and weighed each loco; Thomas = 61 grams and Billy = 54 grams, and to equalize the mass I taped a NZ 10c coin (3.3g) + 20c coin (4.0g) to Billy.

To ensure that variable track friction wasn't a factor, I placed both locos on the kitchen bench top and pushed both in the same direction together. They both came to a stop with Thomas slightly ahead by 2mm after traveling about 80cm from the point where the propelling force ceased.

Now these bench top tests with kids toys are far from the ideal, yet they are capable of demonstrating the not so obvious.
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