- #1

maccam912

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## Homework Statement

While walking between gates at an airport, you notice a child running along a moving walkway. Estimating that the child runs at a constant speed of 2.9 m/s relative to the surface of the walkway, you decide to try to determine the speed of the walkway itself. You watch the child run on the entire 19-m walkway in one direction, immediately turn around, and run back to his starting point. The entire trip takes a total elapsed time of 32 s. Given this information, what is the speed of the moving walkway relative to the airport terminal?

## Homework Equations

v = d/t

## The Attempt at a Solution

I know that the child's velocity relative to the ground in one direction is (x+2.9) (where x is the speed of the moving walkway) and in the other direction it is (x-2.9). We did a similar problem to show that average speed is not necessarily the speed in one direction+the speed in the other direction/2.

I know that the whole distance traveled is 19*2 meters, or 38 meters. I also know that it takes the child 32 seconds to do this overall, so the average speed is (38/32) meters/second. With that information, I made this equation:

(x+2.9) * t

_{one way}+ (x-2.9) * (32-t

_{one way}) = 38/32. Time (t) will be the same in both of those, since the time to run the other way is taken care of by subtracting the first t from 32 for the return trip. I need x, but I still have 2 variables. Thanks in advance for helping me out.