Question

The equation for the vibration of a string fixed at both ends vibrating in its third harmonic is given by `y=2cm` `sin[(0.6cm^-1)x]cos[(500pis^-1)t]`. The length of the string is
A. `24.6 cm`
B. `12.5 cm`
C. `20.6 cm`
D. `15.7 cm`

Answer 1

Correct Answer - D
Wave number `K=(2pi)/(lamda)=0.6cm^-1`
`:. (lamda)/(2)=(pi)/(0.6)cm`
`:. l=(3lamda)/(2)3((pi)/(0.6))cm=15.7cm`