Philadelphia Drivers License Practice Test

What is the stopping distance on a dry concrete road at 50 mph?

1. 150 ft

2. 200 ft

3. 243 ft

4. 300 ft

The correct answer is: 243 ft

The stopping distance on a dry concrete road at 50 mph can be determined by considering the various components that contribute to stopping distance, which include perception distance, reaction distance, and braking distance. At 50 mph, the average stopping distance from a dry concrete surface is approximately 243 feet, which is the correct answer. This distance includes the time it takes for a driver to perceive a need to stop and the time it takes for the vehicle to come to a complete stop once the brakes are applied. When the vehicle is traveling at a higher speed, both the perception and reaction times significantly increase the total distance needed to stop safely. The kinetic energy of the vehicle also plays a key role since it increases with the square of the speed; this means that obstacles or hazards may require more distance to overcome at increased speeds. Hence, the calculation for stopping distance at 50 mph typically results in around 243 feet under ideal conditions on dry pavement. It's important to understand how these factors interact, as they reflect real-world driving scenarios and highlight the significance of maintaining safe speeds and following distances.