How often do you see square of sinusoidal graph?
1. In SHM , where the velocity is sinusoidal and hence kinetic energy is square of sine graph . Since PE + KE = total energy , PE is also square of sinusoidal graph.
2. In AC, the current and voltage is sinusoidal and hence power is square of sinusoidal graph as P = I2R or v2/R.
