Asked by Anne
A car is being driven along a country road on a dark and rainy night at a speed of 20 m/s. The section of road is horizontal and straight. The driver sees that a tree has fallen and covered the road ahead. Panicking, the driver locks the breaks at a distance of 20m from the tree. If the coefficient of friction between the wheels and road is 0.8, at what speed does the car crash into the tree?