Stopping Distance Lab Report

The purpose of this experiment was to determine the relationship between the stopping distance and the initial velocity of the car before braking on different road conditions. In this experiment, a car is driven at different speeds on dry and wet road conditions. The braking distance is then measured, and the coefficient of friction is determined with the information recorded. The stopping distance, oftentimes called braking distance, is the distance that a car travels while slowing to a complete stop. There are many variables that affect the braking distance that one should consider while driving to insure that there is enough room to come to a complete stop without a collision. The slope of the road is a variable that affects the braking

To do the experiment, two people were needed. One person was the driver and another was the measurer. The measurer stood at a selected position while the driver started at a distance far enough away to be able to catch up to a selected constant speed. In this case, it was either 15 mph, 25 mph, or 35 mph. When the driver got to where the measurer was, a brake was applied. From where the measurer was standing, the distance was measured to where the car stopped. This distance was then recorded. For each speed, three trials were conducted. Next, the road condition was changed to wet. A hose was used to spray a large piece of area with water. Then the process is repeated.

Using the average distances, the equations d = (v02)/(2μg) and Ff = μFn were used to determine μ and the force of friction which are shown in Table 3. From the calculations, the average coefficient of friction on dry road was 0.705 and the average frictional force was 8016.27 N. The average coefficient of friction on wet road was 0.553 and the average frictional force was 6299.6 N. From the data, it is concluded that with a higher speed, the distance it takes to come to a complete stop is higher. The data also shows that wet road conditions decrease the coefficient of friction and frictional