8.To transmit a transverse waves with an average power Pav, speed v, amplitude A and angular frequency w, along a stretched string with a tension F and a linear density μ. If the tension increased fourfold, the wave velocity becomes v'. With the wavelength unchanged, the new frequency is w'. If the same amount of average power (P'av =Pav) is transmitted as before, but with this new w', then the ratio of the new amplitude to the original amplitude must be (A) 0.25(B) 0.35 (C) 0.5 (D) 0.7 (E) 1.