Transverse waves travel with a speed of `20.0 m//s`in a string under a tension of 6.00 N. what tension is requared for a wave speed of `30.0 m//s` in the same string?

Explanation

The two wave speeds can be written as:
`v_(1)=sqrt(T_(1)//(mu) and t_(2)=sqrt(T_(2)//mu)`
dividing the equations
`v_(2)/v_(1)=sqrtT_(2)/T_(1)` so that `T_(2)=(v_(2)/v_(1))^(2) T_(1)`
`T_(1)=((30.0)/(20.0))^(2) (6.00 N)=13.5 N`