Q. Equation of a progressive wave is given by $y = 4\sin\left\{ \pi\left( \frac{t}{5} - \frac{x}{9} \right) + \frac{\pi}{6} \right\}$ Then which of the following is correct
A) $v = 5m/sec$
B) $\lambda = 18m$
C) $a = 0.04\ m$
D) $n = 50\ Hz$
Explanation
(b) From the given equation amplitude $a = 0.04m$
Frequency $= \frac{Co - efficient\ of\ t}{2\pi} = \frac{\pi/5}{2\pi} = \frac{1}{10}Hz$
Wave length $\lambda = \frac{2\pi}{Co - efficient\ of\ x} = \frac{2\pi}{\pi/9} = 18m$
Wave speed $v = \frac{Co - efficient\ of\ t}{Co - efficient\ of\ x} = \frac{\pi/5}{\pi/9} = 1.8m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.