If a vehicle goes twice as fast, how much will the stopping distance increase?

When a vehicle's speed doubles, the stopping distance increases by a factor of four. This is due to the physics of motion and the relationship between speed and the distance required to stop.

Stopping distance is comprised of two components: reaction distance and braking distance. Reaction distance is how far a vehicle travels during the driver's reaction time, while braking distance is how far it travels while braking to a stop.

When speed increases, the reaction distance increases linearly—meaning if you double the speed, you will also double the distance traveled during your reaction time. However, braking distance increases with the square of the speed. Therefore, if the vehicle's speed is doubled, the amount of force needed to stop it increases significantly due to the kinetic energy, which is proportional to the square of the speed.

As a result, the total stopping distance becomes four times greater when the speed is doubled, making option C the correct choice. This principle highlights the importance of maintaining safe driving speeds, as higher speeds not only require longer distances to stop but also increase the potential for accidents.