The driver of a car is travelling on a wet, level road, and slams on the brakes. The car slides 88M to a stop, with a coefficient of friction of 0.42. What was the initial speed of the car?
KE = .5mv2
Δd = v1Δt + .5aΔt2
Any other kinematics, dynamics, and work/energy/power equations.
The Attempt at a Solution
I have tried subbing equations together but I always end up with 3 variables, v1, a, and Δt. I feel like mass is required for any solution, because then friction could be calculated and the rest would be simple.