Answer
The tension in the rope is $~~240~N$
Work Step by Step
We can find the wave speed:
$v = \lambda~f$
$v = 2L~f$
$v = (2)(2.0~m)~(5.0~Hz)$
$v = 20~m/s$
We can find the tension in the rope:
$v = \sqrt{\frac{\tau}{\mu}}$
$v = \sqrt{\frac{\tau}{m/L}}$
$v = \sqrt{\frac{\tau~L}{m}}$
$v^2 = \frac{\tau~L}{m}$
$\tau = \frac{v^2~m}{L}$
$\tau = \frac{(20~m/s)^2~(1.2~kg)}{2.0~m}$
$\tau = 240~N$
The tension in the rope is $~~240~N$
