Question

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

• A. $80m{s}^{-1},40m{s}^{-1}$
• B. $40m{s}^{-1},80m{s}^{-1}$
• C. $80m{s}^{-1},63m{s}^{-1}$
• D. None of these

Answer 1

The correct option is C $80m{s}^{-1},63m{s}^{-1}$

$v=\sqrt{\frac{T}{\mu }}\Rightarrow v_{AB}=\sqrt{\frac{6.4\times 10}{10\times {10}^{-3}}}=80m{s}^{-1}$
$v_{CD}=\sqrt{\frac{3.2\times 10}{8\times {10}^{-3}}}=63m{s}^{-1}$