One end of `12.0m` long rubber tube with a total mass of `0.9kg` is fastened to a fixed support. A cord attached to the other end passes over a pulley and support an object with a mass of `5.0kg`. The tube is struck a transverse blow at one end. Find the time required for the pulse to reach the other end.`(g=9.8m//s^(2))`

Answer

A, B, D

Explanation

Tension in the rubber tube AB, `T=mg`
or `T=(5.0)(9.0)=49N`
Mass per unit length of rubber tube, `mu=(0.9)/(12)=0.075kg//m`
:. Speed of wave on the tube, `v=sqrt((T)/(mu))=sqrt((49)/0.075)=25.56m//s`
`:.` The required time is,`t = (AB)/(v)=(12)/(25.56)=0.47s`