Question

The Coefficient of kinetic friction between the tires of your car and the roadway is "μ". (a) If your initial speed is "v" and you lock your tires during breaking, how far do you skid? (b) What is the stopping distance for a truck with twice the mass of you car, assuming same initial speed and coefficient of kinetic friction.

Answer 1

U = v.
V (final speed, not the same as v) = 0.
F = -μN = ma. Solve for a, make sure it's negative.

Now you have U, V and a. You want to find x.
V^2 = U^2 + 2ax, solve for x.

Next time, just use 2m instead of m. Compare the results.