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I know kinetic energy is due to motion of an object. But what if, I, the observer of an object is moving and that object appears to be moving for me, then which one has kinetic energy. is it me or that object?I mean the object doesn't actually move but it appears to be moving because I am moving.

dmckee --- ex-moderator kitten
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Chin chin
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  • Of course , you have a kinetic energy ... – Nehal Samee Mar 12 '18 at 07:21
  • The cause for which the object moves in your reference frame is the pseudo force ... This is an imaginary force ... I think kinetic energy of object is absent... – Nehal Samee Mar 12 '18 at 07:23
  • @NehalSamee Force and energy are different things! Kinetic energy consists of mass and a velocity. Force is all about acceleration. – Metalbeard Mar 12 '18 at 08:32
  • So , @Aziraphale...So you say that the object has kinetic energy even though it's not moving in the platform while moving in the train frame... – Nehal Samee Mar 12 '18 at 09:19
  • @NehalSamee, it all depends on the reference frame. If you use the train as refrence, the whole landscape is whooshing by with $-V_train$ plus its own motions (cars, wind, birds, humans etc.). Have a look at the Wikipedia entry. There is a section "Frame of reference" (see answer below). – Metalbeard Mar 12 '18 at 11:39

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Kinetic energy depends on the reference frame of an observer. Therefore, kinetic energy is not a property of an object only: If you are moving along with an object and you define yourself as reference, then the kinetic energy of the object is zero (in this special reference frame).

The English Wikipedia article on Kinetic Energy has a section "Frame of reference" where this is explained in detail.

Metalbeard
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