stopped at a red light. The bumpers? A 1.0*10^3 kg Toyota collides into the rear end of a 2.2*10^3 kg Cadillac stopped at a red light. The bumpers lock, the brakes are locked, and the two cars skid forward 2.4 m before stopping. The police officer, knowing that the coefficient of kinetic friction between tires and road is 0.42, calculates the speed of the Toyota at impact. What was that speed?