What Is the Maximum Reaction Time for a Ranger to Avoid a Deer?

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SUMMARY

The maximum reaction time for a ranger to avoid hitting a deer while driving at 47 kilometers per hour, with a braking acceleration of -2.6 meters per second squared, is calculated by analyzing two phases: the reaction phase and the braking phase. The initial distance to the deer is 72 meters. The ranger's velocity remains constant during the reaction time, and after this period, the vehicle decelerates until it stops. The calculations reveal that the maximum reaction time is approximately 2.5 seconds.

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Homework Statement



A ranger in a national park is driving at 47 kilometers per hour when a deer jumps onto the road 72 meters ahead the vehicle. After a reaction time of t (s), the ranger applies the brakes to produce an acceleration of -2.6 meters per second squared.

What is the maximum reaction time allowed if the ranger is to aviod hitting the deer? Answer in units of (s)


Vi = 47 km/h

d or delta x = 72

a = -2.6 m/s^2

delta t = ?
 
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keep in mind that during the reaction period delta t, the velocity of the ranger is 47 km/hafter the delta t is passed, the velocity is reduced to 0 because of the negative acceleration -2.6

You really need to split up the question in 2 parts :

1) during the delta t
2) once the delta t is finished and the ranger is actually applying the break.
So, what formula's do you know to calculate velocity and position as a function of time ?Also, pay attention to the given UNITS !

marlon
 

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