Find time given velocity and distance

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To determine the magnitude of acceleration produced by braking, the vehicle's stopping distance of 29 m at a speed of 28 m/s results in an acceleration of 13.52 m/s². For the jaywalker positioned 27 m in front of the vehicle, the time taken for the vehicle to cover this distance can be calculated using the kinematic equations. By applying the equation x = v₀t + ½at², the time can be derived from the known values. The key focus is on calculating the time it takes for the vehicle to reach the pedestrian before stopping. This analysis emphasizes the urgency for the pedestrian to react quickly.
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Homework Statement



A certain vehicle requires a distance of 29 m to stop when it is traveling at 28 m/s.
(a) What magnitude of acceleration is produced by braking under these conditions?
(b) If a jaywalker is 27 m in front of the vehicle when the driver first applies the brakes, how much time does the pedestrian have to get out of the way?

Homework Equations



v=vo + at
x - xo = vot + \frac{1}{2}at2
v2 = vo2 + 2a(x - xo)

are the given equations for what we're learning.

The Attempt at a Solution



(a) 13.52m/s2
(b) is what I cannot find
 
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I'll rephrase the question: How long does it take the vehicle to cover 27 m?
 

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