Final answer:
To ensure you are a safe distance behind a truck, calculate stopping distance considering the truck's speed, reaction time, and deceleration rate. A safe following distance is often considered to be at least 3-4 seconds behind the vehicle in front in dry conditions. Adjust your distance based on these factors to avoid collisions.
Step-by-step explanation:
To tell if you're a safe distance behind a truck, you should be aware of several factors including the distance the driver covers before hitting the brakes, the truck's stopping time after brakes are applied, and the total distance covered to come to a complete stop. For instance, if a truck is traveling at a constant velocity of 10 m/s and it takes the driver 0.5 seconds to react and start braking, and the truck decelerates at a rate of -1.25 m/s², you would use these figures to calculate the stopping distance.
The formula for calculating stopping distance is: stopping distance = reaction distance + braking distance. The reaction distance is the speed of the truck times the reaction time of the driver. In this case, it would be 10 m/s multiplied by 0.5 s, yielding 5 meters. Next, you need to calculate the braking distance using the deceleration and the initial speed, which can be found using the formula s = (v²)/(2a), where 'v' is the initial velocity and 'a' is the deceleration rate.
As a rule of thumb, a safe following distance might be at least 3-4 seconds behind the vehicle in front of you in dry conditions, and this would increase in poor conditions. Thus, when trying to determine if you are at a safe distance behind a truck to avoid collisions, consider your speed, the truck's potential stopping distance, and adjust your following distance accordingly to ensure safety.