Physics  please, I really need help
posted by Sam on .
a car attempts to stop and slides 25.5m while accelerating at 4m/s^2. The car's initial velocity was 20m/s. Find the time the slide took. Note that the final velocity is not known and that you need a quadratic solution.
I know the quadratic formula, but I'm not sure how to plud in the values; could sombody please calrify. Thank you in advance. :)

Vf^2=Vi^2 +2a* disance
find Vfinal first. You have Vi, a, distance. Remember a is negative.
Now, knowing Vf.
Vf=Vi+ a*time
Now find time.
YOu do not need the quadratic formula.