Final answer:
The weight of the vehicle affects its stopping distance, as a heavier vehicle has more momentum and requires a greater force to stop. This leads to a longer stopping distance, especially in adverse road conditions or at higher speeds. Stopping distance includes both reaction distance and braking distance.
Step-by-step explanation:
The weight of the vehicle impacts the stopping distance significantly. When a driver hits the brakes, the stopping distance is influenced by the vehicle's momentum, which is the product of its mass (or weight) and velocity. A heavier vehicle has more momentum at a given speed than a lighter one, which means it needs a greater stopping force and a longer distance to come to a complete stop. The stopping distance consists of two main components: the distance the vehicle travels while the driver is reacting, known as the reaction distance, and the distance the vehicle travels after the brakes are applied, known as the braking distance.
According to Newton's second law of motion, a greater force is needed to change the momentum (stop) a heavier vehicle than a lighter one. The stopping distance is further affected by road conditions; for instance, wet pavement can significantly increase the required distance for a vehicle to stop. Furthermore, a vehicle's initial speed greatly affects the stopping distance. It's noted that a car going twice as fast does not stop in twice the distance—it covers much more ground before coming to a halt.
We calculate the total distance to stop by adding the distance covered during the driver's reaction time, which can be assumed to have constant velocity, to the stopping distance on either dry or wet concrete. Safety features like airbags are designed to increase the amount of time over which the stopping force is applied, reducing the net force and thus the impact on the occupants.