When you double the speed of a car, you increase the potential force of impact by:
- Two times.
- Three times.
- Four times. ✓
- Nothing.
Answer: C. Four times.
When you double the speed of a car, the potential force of impact goes up four times.
Why this is the answer
The handbook states the relationship directly: doubling speed makes the force of impact four times greater, and tripling speed makes it nine times greater. That is why the faster you drive, the greater the striking power of your vehicle. The same passage also ties this to stopping: doubling speed means both braking distance and impact are four times greater. So the change is not simple addition — speed multiplies the effect on impact.
Why the other answers are wrong
- A. Two times. — Two times is wrong because the handbook says doubling speed raises impact force four times, not twice.
- B. Three times. — Three times is wrong because the handbook gives three times as a step in the example only for tripling speed, which yields nine times the impact.
- D. Nothing. — Nothing is wrong because the handbook says plainly that the faster you drive, the greater the impact or striking power.
Remember it
Square the speed multiple: double gives four, triple gives nine, quadruple gives sixteen.
Official handbook: Florida Driver License Handbook (FLHSMV), 7. Driving Safety – Turning, p. 68