Answer
$v=82\frac{m}{s}$
Work Step by Step
We know that,
$v=\sqrt\frac{T}{\mu}$
But also:
$\mu=\frac{M}{L}$
Hence, the two equations above can be combined to form the formula: $v=\sqrt\frac{TL}{M}$
We plug in the known values to obtain:
$v=\sqrt\frac{96(8.40)}{0.12}=82\frac{m}{s}$
