JEE Main2017PhysicsWaves and SoundActual
A standing wave is formed by the superposition of two waves travelling in opposite directions. The transverse displacement is given by, y x , t = 0.5 sin ⁡ 5 π 4 x cos ⁡ 200 π t . What is the speed of the travelling wave moving in the positive x direction? ( x and t are in meter and second, respectively)
Options
- A120   m   s - 1
- B90   m   s - 1
- C160   m   s - 1
- D180   m   s - 1
Correct answer
C. 160   m   s - 1
Step-by-step solution
y = 2 a sin k x cos ω t ⇒ k = 5 π 4   m - 1 ,   ω = 200 π   rad   s - 1 , v = ω k = 200 π 5 π 4 = 160   m   s - 1