When your speed is doubled, how is the braking distance affected?

Answer: C — It is four times longer

When your speed is doubled, the braking distance indeed becomes four times longer due to the physics of motion and energy. The braking distance is influenced by the kinetic energy of the vehicle, which is calculated based on the formula for kinetic energy: KE = 1/2 mv², where m represents mass and v represents velocity. When you double your speed, the velocity (v) in this equation is squared. For example, if the initial speed is v, when it's doubled, the new speed becomes 2v. Substituting into the kinetic energy formula gives you KE = 1/2 m(2v)², which simplifies to KE = 1/2 m(4v²), indicating that the kinetic energy—and thus the stopping distance—quadruples when speed is doubled. This principle is crucial for understanding how speed affects stopping distance in real-world driving scenarios. A driver should be aware that as speed increases, the required distance to safely stop increases significantly, making it vital to adjust driving behavior accordingly at higher speeds.