posted by krysta .
Use the following situation to answer the next four questions. The formula for these questions came from the police department. They use this formula to determine the speed at which the car was going when the driver applied the brakes, by measuring the distance of the skid marks. So when you get to problem 16, it is referring to what a person would interpret the situation if the skid mark was zero distance. So, if the skid mark distance equaled zero, that would mean, the speed of the vehicle, r, was zero, or that the car was able to stop instantly. For these questions, the equation d = 0.05r2 + r models the distance, d, in feet traveled by a car moving r miles per hour (r is the speed of the car) after the driver begins to stop the car.