## Kinetic energy formula.

Hi!
The kinetic formula are EK=1/2*m*v^2. But how do we find it?

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 Mentor Blog Entries: 1 Looks like you already found it! What do you mean? (How you would find the kinetic energy in a particular problem will depend on the details of that problem.)
 Maybe he/she meant to ask how the formula is derived.

Recognitions:

## Kinetic energy formula.

The simplest derivation is to consider how much work is done to accelerate an object to velocity v. Lets say we use constant force to accelerate the object over some distance d.

F = ma -> a = F/m (From Newton's 2nd)

W = F*d (From definition of work.)

vē = 2*a*d (Let us know if you need help deriving this one, but you should have seen it.)

Putting it all together.

vē = 2*d*a = 2*d*(F/m) = 2*(d*F)/m = 2*W/m

W = (m*vē)/2

So the amount of work required to accelerate (or decelerate, for that matter) an object of mass m to velocity v is (1/2)*m*vē. Hence the Kinetic Energy.

 Mentor Blog Entries: 1 Anyone else want to guess what the OP's real question was?

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