Angular Acceleration of toy train

AI Thread Summary
The discussion focuses on calculating the angular acceleration of a toy train on a horizontal track with a diameter of 1.4 meters and a rolling friction coefficient of 0.12. The participants clarify that to find the angular acceleration, one can use the relationship between linear acceleration and angular acceleration, even without a specific mass value, as it cancels out in the equations. The calculated angular acceleration is determined to be 1.68 rad/s². Additionally, the time taken for the train to stop from an initial angular speed of 16 rpm is also a point of interest, although not fully explored in the discussion. Overall, the thread emphasizes problem-solving in physics related to angular motion.
carleon
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Hi, thanks for taking a look!

A toy train rolls around a horizontal 1.4-m-diameter track. The coefficient of rolling friction is 0.12.
(a) What is the magnitude of the train's angular acceleration after it is released?
(b) How long does it take the train to stop if it's released with an angular speed of 16 rpm?

I think I know which equations to use: α = ω^2*r and a = rα, but there is no mention of velocity in the problem so I am stuck.
 
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welcome to pf!

hi carleon! welcome to pf! :smile:
carleon said:
(a) What is the magnitude of the train's angular acceleration after it is released?

find a (from F = ma), then divide by r to get α :wink:
 


Thanks, but since mass isn't given, how would I find F=ma?
 
call the mass "m" … it'll cancel :smile:
 
I got it! α=1.68rad/s^2

Thanks a bunch. :biggrin:
 

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