Conservation of energy of ball with drag

[simplemail1]

Homework Statement

A .63 kg ball is thrown up with an initial speed of 14 m/s and reaches a maximum height of 8.1m. How much energy is dissipated by the air drag acting on the ball during the ascent?

Homework Equations

KE= 1/2MV^2

The Attempt at a Solution

I'm not very good at physics. I think I have to find the joules by plugging in the numbers accordingly in the equation, but I don't know what to do from there...

KE = .5(.63)(14)^2 = 61.74

The actual answer is -12 J >.<

 

[Dick]

Compare the change in kinetic energy with the change in potential energy. Which is mgh. The difference is the loss to friction.