(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A race car fan is sitting in the first row at the beginning of a 1.5 km front stretch of a racetrack. A race car driver coming around the final turn is approaching the fan’s position at 99.5 m/s. The driver sees a car wreck ahead and slams on the brakes causing the car to slow at 4.7 m/s2. Unfortunately, the driver crashes into the wreck at 27.3 m/s. If the speed of sound in the air is 343 m/s, how much time elapses from the moment the fan sees the crash and when the fan hears the crash?

2. Relevant equations

v=fλ

d=vt

3. The attempt at a solution

using the info:

v1= 99.5 m/sec v2=27.3 m/sec

i tried to use d=vt to find the t(ime) but i couldnt figure out d.

Eventually i got that t=1.53 by using v2=vi+at and d=vit+0.5at^2, but the correct answer should be 2.8s??? I dont know how to get there

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# Homework Help: Time elapsed between seeing a crash and hearing the crash

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