A truck is traveling at 35 m/s on a slippery road. the driver slams on the brakes and the truck starts to skid. if the coefficient of kinetic friction between the tires and the road is 0.20, how far will the truck skid before stopping?
m = the mass of the truck N = normal reaction g = 9.8 m/s² μ = 0.2, the coefficient of kinetic friction
The resistive force on the truck is F = μN = μmg = 0.2*(9.8)m = 1.96m N The acceleration (actually deceleration) is a = F/m = -1.96 m/s²
Let d = distance for the truck to come to rest from an initial velocity of u = 35 m/s. Then u² + 2ad = 0 (35 m/s)² + 2(-1.96 m/s²)(d m) = 0 d = 35²/3.92 = 312.5 m
