Halliday 2 Cap 18 - P18 085

Transcript

85. (a) The frequency at which λ = D is f1 = v 343 m/s = = 2.29 × 103 Hz , D 15.0 × 10−2 m the frequency at which λ = 10D is f2 = 2.29 × 102 Hz, and the frequency at which λ = 0.1D is f3 = 2.29 × 104 Hz. (b) Now, D = 30.0 cm. The frequency at which λ = D is f1 = v/D = (343 m/s)/(30.0 × 10−2 m) = 1.14 × 103 Hz, the frequency at which λ = 10D is f2 = 1.14 × 102 Hz, and the frequency at which λ = 0.1D is f3 = 1.14 × 104 Hz.