The stationary waves set up on a string have the equation :
`y = ( 2 mm) sin [ (6.28 m^(-1)) x] cos omega t`
The stationary wave is created by two identical waves , of amplitude `A` each , moving in opposite directions along the string . Then :

Options

A. A = 2 mm
B. A = 1 mm
C. The smallest length of the string is 50 cm
D. The smallest length of the string is 2 m

Answer

B, C

Explanation

Comparing with the equation
`2Asin((npix)/(L))cos(omegat)`
`2A=2mmor A=1mm`
`(npix)/(L)=6.28x=2pixor L=(n)/(2)m`
For `n =1,L=0.5m`.