K.E=P.E=net work done?

K.E=P.E=net work done?
Actually, it is increase in K.E.=Work Done or increase in P.E.=Work Done
以下有一段證明,如果你可以認真睇清楚,應該就會明.
Increase in K.E.
=0.5mv^2-0.5mu^2
=0.5m(v^2-u^2) (Note that v^2-u^2=2as)
=0.5m(2as)
=mas
=Fs=W 所以話Increase in K.E.=Work done
Increase in P.E.
=mgh2-mgh1
=mg(h2-h1)
=mg(displacement)
=Ws
=Fs=W 所以話Increase in P.E.=Work done,而呢個work done係地球比出黎.