Newton's Laws: Distance of a car accelerating, then slamming on the breaks.

AI Thread Summary
A car with a mass of 1980 kg accelerates under a net force of 32,000 N, resulting in an acceleration of 16.16 m/s². After 12 seconds, the driver applies the brakes, and the force of friction is calculated using the coefficient of kinetic friction of 0.8, leading to a braking acceleration of -7.84 m/s². The initial velocity at the time of braking is determined to be approximately 193.92 m/s. The total distance traveled by the car is calculated by summing the distances during acceleration and braking phases. This problem highlights the application of Newton's laws and the importance of selecting appropriate equations for motion analysis.
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A car which is originally at rest accelerates down a road with a net force of 32000 N acting on a 1980 kg car. At t = 12 seconds the driver slams on the brakes to avoid hitting a deer. Calculate the distance traveled by the car.
Coefficient of kinetic friction for the rubber on pavement is assumed to be .8


F⃗ net=ΣF⃗ =ma⃗ (a = F/m)
fk=μkN

v=v0+at
x=x0+v0t+(1/2)at2
v2=v20+2aΔx
a = Δv/Δt
blablahblah

Anyone who can tell me how to start this problem?
FBD shows force of friction going -X, normal force y, weight -y.

32000 = 1980a
a = 16.16 m/s2

v = 0 + 16.16x12
v = 193.92 m/s

I obviously have to do a second xvat for t=12 seconds and onward. These net force/ Newtons laws problems are killing me because they involve a lot of creativity with choosing working equations, which I don't have.

Help please!
 
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We know the force from braking is equal to Fn*uk.

Force braking is (1980)(9.8)*.8

acceleration from braking is therefore 9.8*.8 in the negative x direction from F=ma

d1+d2=total distance

d1:

use d1=.5at^2

d2:

use d2=v0t+.5at^2

where a is negative for the d2 equation and I found it above
 
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