A 20 m long truck and a 6 m long car are driving at a speed of 20 m / s on a straight road at a constant speed. The distance between the two cars is 25 M. at present, the car overtakes at an acceleration of 0.5 m / S2. The car does not enter the lane from the overtaking lane until it exceeds 30 m of the truck

A 20 m long truck and a 6 m long car are driving at a speed of 20 m / s on a straight road at a constant speed. The distance between the two cars is 25 M. at present, the car overtakes at an acceleration of 0.5 m / S2. The car does not enter the lane from the overtaking lane until it exceeds 30 m of the truck

(1) Taking the freight car as the reference system, the car does the uniform acceleration motion with the initial velocity of 0 and the acceleration of 0.5 m / S2. According to the geometric relationship, S0 = 20 + 6 + 25 + 30 = 12 × 0.5t2, the solution time t = 18 & nbsp; s, the distance of the car driving in this time is s = v0t + 12at2, and the substitution value is s = 20 × 18 + 12 × 0.5