Question

The diagram 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 velocity of points $1,2$ and $3$ on the string ?

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

Particle velocity $\left(v_p\right)=-v\times \text{Slope of the graph at that point.}$

At point 1: Slope of the curve is positive, hence particle velocity is negative or downward $(\downarrow )$
At point 2: Slope negative, hence particle velocity is positive or upwards $(\uparrow )$
At point 3: Again slope of the curve is positive, hence particle velocity is negative or downward $(\downarrow )$