Question

What are the three lowest frequencies for standing waves on a wire 10m long having a mass of 100g, which is stretched under a tension of 1600N?

Answer 1

Here,`l=10m, M=100g=10^(-1)kg.`
`T=1600N`
`m=(M)/(l)=(10^(-1))/(10)=10^(-2)kg//m`
`f_(1)=(1)/(2l)sqrt((T)/(m))=(1)/(2xx10)sqrt((1600)/(10^(-2)))=(400)/(20)`
`=20Hz`
`f_(2)=2f_(1)=2xx20Hz=40Hz`
`f_(3)=3f_(1)=3xx20Hz=60Hz`