The car moves at uniform acceleration on a 1 km section of road. The initial speed is 40 km / h

The car moves at uniform acceleration on a 1 km section of road. The initial speed is 40 km / h, and the final speed is 80 km / h. how long did he drive on this site?

Let us first calculate the acceleration with which the car was moving along the entire path:

a = (v² – v0²) / (2 * S) = 5/27 m / s.

The equation of motion of the car will be described by the following expression:

(5/54) * t² + (100/9) * t – 1000 = 0.

Having solved this equation, we get that the time that the car spent on the way was t = 60 s, i.e. One minute.

Answer: t = 60 s.