A uniform wire of length 20 m and weighing 5 kg hangs vertically. If `g=10 m s^(-2)`, then the speed of transverse waves in the middle of the wire is

Options

A. `10 m//s`
B. `10sqrt2 m//s`
C. `4 m//s`
D. zero

Answer

A

Explanation

Here `m=5/20 kg//m=1/4 kg//m`
Tension in the middle of the wire
T= weight of half of wire `=5/2 times g=5/2 times 10N=25N`
As `v=sqrt(T//m) therefore v=sqrt(25/(1//4))=1 m//s`