prove that the power is 4x if frequency is doubled?

Answer 1

Apparently, the power dissipated is proportional to the square of the frequency.

This is like a riddle--I can't think off the top of my head what system you are talking about--an AC circuit with a capacitor and a resistor perhaps? The mechanical analog would be a spring and a dashpot.

Wanna give us a hint?

Answer 2

if it's smth like pendulum or circuit, its can be described by eq:
x''+w^2*x=0, where w^2=k/m
x-coordinate, w-frequency
the solution is smth like x(t)=a*cos(w*t+f0) (1), a-amplitude, f0-starting phase. Consequently, E=T+U= {m*(x')^2}/2 + {k*x^2}/2=then goes simple math using condition (1)={m*a^2*w^2}/2
So we get W prop. to w^2 i.e. x4 if frequency doubles

Answer 3

How will you ever know if the 'answer' given here is correct if you don't do your own Homework ?