80. The train is moving in a straight line at a speed of υ0 = 180 km / h. Suddenly, on the way there is an obstacle and the driver includes a brake. Since then, the train speed varies as υ = υ0 - αt2, where α = 1 m / s3. What is the braking distance of the train? How soon after the start of braking to stop it?

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)