a model electric train makes one complete pass around a circular track every 15 seconds….?

Question by moniquew93: a model electric train makes one complete pass around a circular track every 15 seconds….?
a model electric train makes one complete pass around a circular track every 15 seconds. the train’s motor has a resistance of 6.0ohm and is connected to a 70.0V source. How much energy will the train use in 12 complete passes around the track?

Best answer:

Answer by kirchwey
This question cannot be answered. Model-train motors don’t draw the huge wattage implied by the voltage and resistance, which = V^2/R = 816.67 W. At running speed the motor would generate a back EMF which would substantially reduce the actual voltage across the internal resistance. See the ref.
EDIT: The input data are not necessarily crazy, just incomplete. What’s crazy is the assumption that the given V is applied across the given R continuously; it actually would only happen momentarily at startup.

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