4. A truck's brakes are applied so hard that the truck goes into a skid on the dry asphalt road (µ = 1.0 - Table 1/P.53).If the truck and its contents have a mass of 4.2 x 10³ kg, calculate the magnitude of the force of kinetic fricition on the truck. Use a FBD of the situation to help answer this question.

Fig: 1