The extension in a string obeying Hooke's law is x. The speed of sound in the stretched string is `v`. If the extension in the string is increased to `1.5 x`, the speed of sound will be

Options

A. 1.22v
B. 0.61v
C. 1.50v
D. 0.75v

Answer

A

Explanation

According to Hooke.s law `F_R prop x`
Velocity of sound by a stretched string `v=sqrt(T/T.)`
Hence `v prop sqrtTor v/v.=sqrt(T/T.)`
or `v.=v sqrt((T.)/T)=vsqrt((1.5x)/x)=1.22v`