A transverse periodic wave on a string with a linear mass density of `0.200 kg//m` is described by the following equation
`y = 0.05 sin(420t - 21.0 x)`
where `x` and `y` are in meters and `t` is in seconds.
The tension in the string is equal to :

Options

A. 32 N
B. 42N
C. 66N
D. 80N

Answer

D

Explanation

We use wave speed
`v = sqrt((T)/(mu)) = (omega)/(k)`
`T = (omega^(2)mu)/(k^2) = (420/21)^(2) xx 0.2 = 80N.`