Question

FIGURE EX17.3a is a snapshot graph at t = 0 s of two waves approaching each other at 1.0 m/s. At what time was the snapshot graph in FIGURE EX17.3b taken?

Short answer

At t = 3sec

Step-by-step solution

Given Information

In graph a, we are given two waves approaching each other with speed 1m/s.

In graph b we have a snapshot of some future instance of graph a.

Comparing both graphs

In graph a initial point of left wave on x axis is at x = 0

In graph b initial point of the wave on x axis is at x = 3.

And the wave is moving towards right with speed of 1m/s.

So this means it must have taken 3 seconds for this initial point to travel from x = 0 to x = 3.

Therefore the snapshot is captured at t=3sec.