Assuming good traction and constant vehicle speed, if you double your vehicle's weight, your vehicle's braking distance will be
- eight times as long.
- quadrupled.
- tripled.
- doubled. ✓
Answer: D. doubled.
With good traction and steady speed, doubling your vehicle's weight doubles your braking distance.
Why this is the answer
The handbook's speed and weight facts say that twice the vehicle weight calls for twice the stopping power, while weight left unchanged with speed doubled calls for four times the stopping power. Since the question holds traction and speed constant and only the weight changes, the extra weight goes up in a straight one-to-one relationship: two times the weight means two times the stopping power, so the distance needed to stop goes up the same amount. That is why the answer is doubled rather than multiplied by four or eight.
Why the other answers are wrong
- A. eight times as long. — Eight times as long is what the handbook gives when both speed and weight are doubled together, not weight alone.
- B. quadrupled. — Quadrupling is tied to doubling the vehicle's speed, which needs four times the stopping power, so it does not fit a weight-only change.
- C. tripled. — The handbook never pairs a tripled figure with any doubling of weight or speed.
Remember it
Keep the two multipliers apart in your head: weight doubles, stopping power doubles; speed doubles, stopping power goes up four times.