A transverse wave travels along a rope. The graph shows the variation of the displacement of the particles in the rope with distance along it at a particular instant.

Question 2

A transverse wave travels along a rope. The graph shows the variation of the displacement of the particles in the rope with distance along it at a particular instant.

 

At which distance along the rope do the particles have maximum upwards velocity?

A 0.5 m                       B 1.0 m                       C 1.5 m                       D 2.0 m

Reference: Past Exam Paper – June 2017 Paper 13 Q22

Solution:

Answer: A.

This question is easily tackled by sketching on the diagram given in the question.

Since the wave is moving to the right, we can draw the position of the wave at the next instant by simply replicating the wave, but shifted to the right.

In this way, we can know how each point has moved in the next instant. It can be seen that particles at both 0.5 m and 1.0 m will move upward at the next instant but the largest upward change in displacement occurs at a distance of 0.5 m.

At 1.5 m and 2.0 m, the particles would move downward in the next instant, and the maximum downward velocity is at 1.5 m.