Energy
I will calculate the energy expended by the signal $ sin(2t) $ from $ t = 0 $ to $ t = 8\pi $ -
$ E = \int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx $
Integration shows us that:
$ \int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx = t/2-\frac{\sin(2t)\cos(2t)}4 $ evaluated from 0 to 8$ \pi $.
$ E = 4\pi $
