In longitudinal waves, the motion of the particles in a medium is across the direction of the wave.
Average speed = (total distance) / (total time)
Average speed = (4+7+1+2 blox) / (1 hour)
<em>Average speed = 14 blocks/hour</em>
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I'm gonna go out on a limb here and take a wild guess:
I'm guessing that there's another question glued onto the end of this one, and it asks you to find either her displacement or her average velocity. I'm so sure of this that I'm gonna give you the solution for that too. If there's no more question, then you won't need this, and you can just discard it. I won't mind.
Average velocity = (displacement) / (time for the displacement)
"Displacement" = distance and direction from the start point to the end point, regardless of how she got there.
Displacement = (4E + 7W + 1E + 2W)
Displacement = (5E + 9W)
<em>Displacement = 4 blocks west</em>
Average velocity = (4 blocks west) / (1 hour)
<em>Average velocity = 4 blocks/hour West</em>
the answer is c) the speed and direction of travel must be constant
