Question

A longitudinal progressive wave is given by the equation $y=5\times {10}^{-2}sin\pi (400t+x)$. The amplitude and wave length of the wave are: [$y,x$ are in $m$].

• A. $A=5\times {10}^{-2}m,\lambda =2m$
• B. $A=5\times 0^{-2}m,\lambda =3m$
• C. $A=5\times {10}^{-2}m,\lambda =4m$
• D. $A=5\times {10}^{-2}m,\lambda =5m$

Answer 1

Answer: (A)

$A=5\times {10}^{-2}m,\lambda =2m$

$y=Asin(\omega t+kx)$

$y=5\times {10}^{-2}sin(\pi t\times 400+\pi x)$

Comparing, we get $A=5\times {10}^{-2}$ and $k=\pi$

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

$\lambda =2m$