Relating friction with acceleration

AI Thread Summary
The discussion revolves around calculating the shortest stopping distance for a car using the coefficient of kinetic friction and its speed. The coefficient of kinetic friction is given as 0.80, and the car's speed is 28.7 m/s. The key realization is that the mass of the car cancels out in the equations, allowing the use of the formula a = μg for deceleration. By applying this understanding, the correct stopping distance can be determined without needing the car's mass. The solution effectively demonstrates the relationship between friction, acceleration, and stopping distance in this context.
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Homework Statement


If the coefficient of kinetic friction between tires and dry pavement is 0.80, what is the shortest distance in which you can stop a car by locking the brakes when traveling at 28.7 m/s?


Homework Equations


The problem doesn't state the mass of the car, so I'm not sure how to exactly relate kinetic friction with the acceleration.


The Attempt at a Solution


v^2 = 0 + 2a(x - 0)
v^2/2a= x

a?
 
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Mass will drop out.

What is the maximum deceleration the car will tolerate?

Won't that be when m*a = μ*m*g ?
 
OHHHH so it doesn't even depend on mass, so I can plug a = ug, which just gave me the correct answer :)

Thanks!
 

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