Approximately, how much does the braking distance of a motorcycle increase if its speed doubles?
Show the correct answer
Correct answer
C. Four times.
Explanation
The question is about how the braking distance of a motorcycle changes when you ride twice as fast. It increases approximately four times - answer C.
Braking distance depends on the energy of motion, and this grows with the square of speed: twice the speed means four times more energy, which the brakes must turn into heat, so the distance is also four times longer. Example: if you stop from 50 km/h in 15 m, from 100 km/h you need about 60 m - and on top of that comes the distance covered during your reaction time, which at 100 km/h is almost 30 m for every second. That is why the Road Traffic Act requires you to ride at a speed that allows you to keep control of the vehicle, taking into account traffic conditions: a safe speed in town is not the one at which you "can still manage", but the one at which you will stop before an obstacle that you only see at the last moment. On a motorcycle this matters twice as much, because if you brake too hard, you lock the wheel and lose balance.
Legal basis: Art. 19 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)