A 1400kg sedan goes through a wide intersection traveling from north to south when it is hit by a 2400kg SUV traveling from east to west. The two cars become enmeshed due to the impact and slide as one thereafter. On-the-scene measurements show that the coefficient of kinetic friction between the tires of these cars and the pavement is 0.750, and the cars slide to a halt at a point 5.51m west and 6.19m south of the impact point.
a) How fast was sedan traveling just before the collision?
b) How fast was SUV traveling just before the collision?