Calculating Car Speed After Sudden Braking

AI Thread Summary
The discussion revolves around calculating the final speed of a car after it suddenly brakes, given an acceleration of -5.6 m/s² over a duration of 4.20 seconds and a distance of 62.4 meters. The equation Xf = Xi + Vi(t) + 1/2at² is suggested as a viable method for solving the problem. Participants confirm that finding the initial velocity (Vi) is essential to determine the final velocity (Vf) after braking. The conversation emphasizes the importance of correctly identifying initial conditions to proceed with the calculations. Overall, the thread focuses on applying kinematic equations to solve for the car's speed upon impact.
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Homework Statement



driver slams breaks. car slows with acceleration of -5.6m/s^2 for 4.20s for 62.4m.

Homework Equations



with wat speed does the car then strike an object?

The Attempt at a Solution



i thought of using equation Xf=Xi+Vi(t)+1/2at^2
i am not sure if this is the best choice but when using this i am getting stuck with the initial velocity. am i in the right track
 
Physics news on Phys.org
Yes, you can use that equation. Find vi, then you can find vf...
 

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