The loudness was increased by the amplifier which converted electrical energy into sound energy.
She does 200J .
We know she uses 20N of force and 10m is the distance. We multiply both numbers and we are given our answer of 200J. Hope this was helpful. :)
Power is the rate of energy. Mathematically, it is
Power (p) = Energy(E) / Time(t)
Hope this helps!
