When car a runs at 20m / s, the driver finds that car B runs at 10m / s in the same direction at 500m ahead on the same straight road. In order to avoid collision, the driver of car a immediately brakes, and calculates the minimum value of a when the driver of car a brakes

When car a runs at 20m / s, the driver finds that car B runs at 10m / s in the same direction at 500m ahead on the same straight road. In order to avoid collision, the driver of car a immediately brakes, and calculates the minimum value of a when the driver of car a brakes

In order to avoid collision between two vehicles, it is necessary to make the two vehicles meet at the same speed. Let the acceleration of vehicle a be a. when the two vehicles have the same speed, for vehicle a: T = v a − v b ax a = v a 2 − v b 22a; for vehicle B: x B = v b T. from the displacement relationship, we can know that: x = x A-X B solution: a = 0.1m/s2. When the driver of vehicle a brakes, the minimum value of a is 0.1m/s2. A: when the driver of vehicle a brakes, the minimum value of a is 0.1m/s2