Question

A triangular wave pulse moving at 2 cm/s on a rope approached an end at which it is free to slide on a vertical pole.

(a) Draw the pulse at `1/2 s` interval until it is completely reflected.
(b) What is the particle speed on the trailing edge P at the instant depicted?

Answer 1

(Reflection of pulse from a free boundry is really the supperposition of two
identical waves travelling in opposite direction. This can be shown as under.
,

In every 1/2s, each pulse (one real moving towards right and one imaginary moving towards left) travels a distance of 1cm as the wave speed is 2 cm/s.
(b) Particle speed, `v_p = |-v(slope)|`
Here, v=wave speed =2cm/s
and slope =1/2
`:. "Particle speed" = 1cm/s` .