A .1 kg object dropped vertically from a height of 1m above the floor bounces back to a height of .8m. What is the mechanical energy lost by the ball?

Question

turingtest · Answer

the energy it lost is the difference between it's two maximum potential gravitational energies
what was the initial gravitational potential energy?
what was it at the high point of it's second bounce?
the difference is the energy that was lost in the impact

anonymous · Answer

ALL of your energy from the start = GPi (gravitation potential initial)  = mass*distance*Acceleration of gravity
GPi= 1*1*9.8

after it bounced  we say final GP

GPf=   1*.8*9.8


GPi-GPf should be answer.

anonymous · Answer

But doesn't KE affect total mechanical energy?

anonymous · Answer

its all based on energy charts tho

anonymous · Answer

I'll draw the situation using 10 energy units arbitrarily chosen 
pe  //////////
ke
at first when 1 off the floor^

pe
ke  //////////
then the exact moment when it hits floor


pe ////////
ke
then it bounced  back up to a new maximum height because it lost energy to the ground. 
LOST 2 units

anonymous · Answer

Well, if you look at only the start and end, I guess so... The answer is right I suppose it's correct. Thank you!