Home › CDL Practice Tests › General Knowledge Questions › Question 28
If you double your speed, what happens to your braking distance and crash force?
- A.Both roughly double
- B.Braking distance triples and force doubles
- C.Braking distance becomes about four times longer, and impact force about four times greater
- D.Nothing changes if the road is dry
Correct answer
C. Braking distance becomes about four times longer, and impact force about four times greater
Why
Braking distance and crash energy grow with the square of speed, so going twice as fast multiplies both by about four. This is why a crash at highway speed is so much more destructive than one at city speed.
Manual topic: Safe Driving - Speed Management · From the General Knowledge practice bank (GK-028).