The distance travelled by a vehicle after the application of brakes to a dead stop position is known as:
- Adistance to react
- Bdeceleration distance
- Cbraking distanceCorrect
- Dstopping distance
Solution
Concept
Braking distance is the distance a vehicle travels from the moment brakes are applied until it stops.
Formula
Braking distance = v2 / (2 g f), SSD = v t + v2 / (2 g f)
Step-by-step solution
1. Stopping distance has two parts: lag distance and braking distance. 2. Lag (reaction) distance is covered before the brakes are applied. 3. The distance covered after the brakes are applied until the vehicle stops is the braking distance. 4. So the answer is (C).
Explanation
When the driver sees an obstacle, the vehicle first moves during the reaction time. This is the lag distance. After the brakes are applied, the vehicle moves some more distance before stopping, and this is called braking distance.
Why the other options are wrong
A: Distance to react is covered before the brakes are applied. B: Deceleration distance is not the standard term used in IRC. D: Stopping distance = lag distance + braking distance, so it is the total, not only the part after braking.
Shortcut
After brakes = braking distance. Total = stopping distance.
Common mistake
Choosing stopping distance, which also includes the reaction (lag) distance.
Correct answer: C) braking distance