Solving for x: A Narrow Bridge Challenge

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SUMMARY

The problem involves calculating the distance from the far end of a 1km bridge where a person must be to reach either end before being hit by a truck traveling at 90km/h. The runner's speed is 5m/s. The key to solving this problem is to express the time required for the runner to reach the nearest end of the bridge as a function of the distance x from that end. The truck's travel time to the end of the bridge must also be calculated, leading to two possible solutions for x based on the time comparison.

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Homework Statement



You are crossing a narrow bridge 1km long when you notice a truck approaching at 90km/h. If you can run at 5m/s, how far from the far end must you be if you could reach either end just before being hit by the truck?

2ltgg1j.jpg


My attempt

Displacement between the two: 1000 - x + d
When displacement is 0, they will meet? I can't seem to solve for x... I end up with more variables than I have equations. :S
 
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Express the time you need to reach bridge end as a function of x, calculate the time truck needs to reach the end of the bridge. If truck needs more time, you will make it.

Note that there are two answers to the question.
 

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