Suppose that the sound level of a conversation is initially at an angry 72 dB and then drops to a soothing 50 dB. Assuming that the frequency of the sound is 507 Hz, determine the
(a) initial and
(b) final sound intensities (in μW/m2) and the
(c) initial and
(d) final sound wave amplitudes (in nm). Assume the speed of sound is 345 m/s and the air density is 1.21 kg/m3.