Delaware Driver Education State Practice Test

What is the maximum distance a vehicle's braking system must stop from at a speed of 20 mph?

1. 40 feet

2. 50 feet

3. 54 feet

4. 60 feet

The correct answer is: 54 feet

To determine the maximum stopping distance for a vehicle traveling at 20 mph, it's essential to consider the physics behind braking. When a vehicle is moving, it possesses a certain amount of momentum that must be overcome by the braking system. The stopping distance comprises two components: the reaction distance, which is the distance covered during the driver's reaction time, and the braking distance, which is the distance it takes to come to a complete stop after the brakes are applied. At 20 mph, various factors influence stopping distance, including vehicle weight, road conditions, and brake efficiency. However, general calculations often estimate that the total stopping distance increases as speed increases. For many vehicles, the average stopping distance at 20 mph can be approximately 54 feet under ideal conditions, taking into account the combined distances covered during the reaction time and the braking process. This standard helps drivers understand the importance of maintaining a safe following distance and being aware of their vehicle's capabilities in emergency situations. Therefore, the correct answer reflects realistic expectations for stopping distances at that speed.