The diagram below shows an instantaneous position of a string as a transverse progressive wave travels along it from left to right Which one of the following correctly shows the direction of the velocity of the points 1,2 and 3 on the string?

Options

A. `rarr` `rarr` `rarr`
B. `rarr` `larr` `rarr`
C. `darr` `darr` `darr`
D. `darr` `uarr` `darr`

Answer

D

Explanation

Particle velocity `(v_p)=-vxx` slope of the graph at that point.
At point 1: Slope of the curve is positive, hence particle velocity is negative or downwards `(darr)` At point 2: slope nigative hence particle velocity is positive or upwards `(uarr)`
At point 3: Again slope of the curve is positive, hence particle velocity is negative or downward `(darr)`