Question

The wave-function for a certain standing wave on a string fixed at both ends is y(x,t) = 0.5 sin (0.025x) cos500t where y and x are in centimeters and t is in seconds. The shortest possible length of the string is

• A. 1.26 m
• B. 1.89 m
• C. 2.52 m
• D. 3.78 m

Answer 1

Answer: (A)

1.26 m

Answer 2

k = $\frac{2\pi}{\lambda}$ = 0.025

⇒ $\frac{\lambda}{2} = \frac{\pi}{0.025}$ = 1.26 m

that is equal to shortest possible length