Final answer:
After driving through water, test your brakes by stopping quickly and firmly from 50 km/h to ensure they function properly and to measure stopping distance or time.
Step-by-step explanation:
After driving through water, you should test your brakes when safe to do so by stopping quickly and firmly from 50 km/h. This safety precaution is important because water can affect braking efficiency by wetting the brake pads and rotors, potentially leading to reduced friction and longer stopping distances. The process of testing your brakes involves accelerating to a set speed—in this case, 50 km/h—and then applying the brakes firmly until the vehicle comes to a complete stop. During this test, you record the stopping distance or the stopping time. These figures are critical for understanding the performance of your brakes under wet conditions and can vary greatly depending on road conditions and driver reaction time. Additionally, when calculating stopping distances, you must consider the car's deceleration rate on different road surfaces, such as dry vs. wet concrete, as well as the driver's reaction time to initiate braking.