This is not so much a homework problem as it is a question:(adsbygoogle = window.adsbygoogle || []).push({});

How do I know whether an object has kinetic energy or potential energy?

I know for potential energy you make a point that is PE(grav) = 0, and then if the object reaches a height you make the other PE = mgh.

So in (KE_2 - KE_1) - (PE_2 - PE_1) - (S_2 - S_1) = W_other where

KE = kinetic en.

PE = potential en

S = spring en

W = other forces acting...

If no other forces are acting on the object W_other = 0; and there is no spring = 0 - 0

Then you get (KE_2 - KE_1) = - PE_2 + PE_1

And then if you make a point that is PE_1 = 0

KE_2 - KE_1 = -PE_2

Then what about KE ? Does that make KE_2 = 0?

I have no idea, please help me! I need an answer in 9 hours!

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# Homework Help: Conservation of energy: How do I know?

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