A student driver is taking a driver's training course with an instructor. A squirrel crosses the street in front of the car. The student slams on the brakes and skids to a stop through a displacement, d. If the car's mass doubles, find the car's skidding distance in terms of d (Note: the initial velocity is conserved) (Hint: Increasing the mass increases the normal force, F n o r m a l = − F g r a v  i t y = m ⋅ g, where the acceleration due to gravity is g = -10.0 m/s2, and friction is directly proportional to the normal force, F f r i c t i o n = F n o r  m a l ⋅ μ, where µ is the coefficient of friction. Also, vf2 = vi2 + 2 ⋅ a ⋅ d).