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An electric train accelerates uniformly from rest to a speed of 20m/s which it maintains until the brakes are applied. It is then brought to rest by a uniform retardation equal in magnitude to twice its former acceleration. The total distance covered is 7.8 km and time taken is is 7 minutes.


  • the time for which the train is travelling at constant speed,
  • the initial acceleration in m/s^2.
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closed as too localized by Waffle's Crazy Peanut, Manishearth Mar 22 '13 at 12:56

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1 Answer

Get a graphical approach to this kind of question.enter image description here

see this V-T graph of the scenario.

You can find everything. the slope gives acceleration.

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