# physics

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A 13.0 {\rm g} plastic ball is dropped from a height of 2.80 {\rm m} and is moving at 3.20 {\rm m/s} just before it hits the floor.
How much mechanical energy was lost during the ball's fall?
delta E mech = ____ J

• physics -

What does your \rm symbol mean? Why do you need a symbol there at all?

delta E mechanical = (Initial PE + KE) - (Final PE + KE)
= MgH - (1/2) M*Vfinal^2

H = 2.80 m is the height of the drop. Initial KE is zero