A wire of length L and mass per unit length 6.0 × 10 - 3 k g m - 1 is put under tension of 540 N . Two consecutive frequencies that it resonates at are: 420 H z and 490 H z . Then L in meters is :

Step-by-step solution

Fundamental frequency = 490 - 420 = 70   H z 70 = 1 2 L T μ ⇒ 70 = 1 2 L 540 6 × 10 - 3 ⇒ L = 1 2 × 70 90 × 10 3 = 300 140 ⇒ L ≈ 2.14   m