Two blocks each having a mass of 3.2 kg are connected by a wire CD and the system is suspended from the ceiling by another wire AB . The linear mass density of the wire AB is 10 g /m and that of CD is `8 g m^-1.` Find the speed of a transverse wave pulse produced in AB and in CD.

Answer

A, C, D

Explanation

`m_1=m_2=3.2kg`
`Mass per unit length of AB
`=10gm/m`
`=0.01kg/m`
`Mass per unit length of CD
`=8gm/m`
`=0.008kg/m`
`For the string CD,
`rarr v=sqrt((T/m))`
`=sqrt((3.2x10)/0.008)`
`=sqrt((32x10^3)/8)`
`=2xx10sqrt10`
`=20xx3.14=63ms`
For the string AB,
`T=2x3.2g=6.4xxg`
`=64N`
`rarr v=sqrt((T/m))`
`=sqrt((64/0.01))=sqrt(6400)`