Speed

What happens to braking distance when speed is doubled?

Question image: What happens to braking distance when speed is doubled?
  • A It doubles
  • B It triples
  • ✓ It quadruples
  • D It increases by 50%

Why this is the correct answer

Braking distance is not proportional to speed but to its square. Therefore, when speed is doubled, braking distance quadruples.

Report an Error

Ready to pass the DGT theory test?

Practise official-format questions in English, with explanations after every answer and full progress tracking.

Try a free practice test