Question

A heavy rope is suspended from a rigid support. A wave pulse is set up at the lowest end, then:

• A. The pulse will travel with uniform speed
• B. The pulse will travel with increasing speed
• C. The pulse will travel with decreasing speed
• D. The pulse cannot travel through the rope

Answer 1

The correct option is B The pulse will travel with increasing speed

The tension in the rope will be increasing along the rope from the lower end to the upper end. It happens because as the we go up the rope, length of rope increases and the tension at a point has to balance the weight of rope below it.
The speed of wave pulse is given as,
$v=\sqrt{\frac{T}{\mu }}$
Where $T\to$Tension in string and $\mu \to$linear mass density of the rope.

$\Rightarrow$Since, $T\uparrow$ as wave pulse travels up the rope, hence its speed will keep on increasing.