Stopping distance: thinking, then braking
"Stopping distance: thinking, then braking" is a free, interactive Class 11 Physics simulation for NEET and JEE, built on the lesson "Stopping distance and reaction time" in Motion in a Straight Line. For the reaction time the car keeps its full speed (yellow). Then the brakes give a steady retardation until it stops (red). Press Play and watch both on the road and on the v–t graph. Stopping distance = v₀t_r + v₀²/2a. The reaction part grows in step with speed, the braking part with its square, so at high speed braking dominates. Convert km/h to m/s (× 5/18) first. JEE Main asked 30 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
From the lesson Stopping distance and reaction time in Motion in a Straight Line. Change the values and watch what happens.
In JEE Main
42 shifts analysed
30 questions from Motion in a Straight Line across the 42 JEE Main shifts Lumi has analysed (2017–2026).
The idea behind it
NCERT § "Kinematic Equations for Uniformly Accelerated Motion"
- A vehicle moving at speed v₀ that brakes with constant retardation a stops in a distance d = v₀²/2a.
- Because d varies as v₀², doubling the initial speed makes the stopping distance four times larger for the same braking.
- Reaction time is the delay between seeing a signal and acting on it; during this time the vehicle keeps moving at its original speed, adding v₀ × (reaction time) to the stopping distance.
- A simple way to estimate reaction time is to catch a falling ruler: if it falls a distance d before being caught, the reaction time is √(2d/g).
- These are applications of the same constant-acceleration equations, not new laws.
Questions
3 answers
- What does the "Stopping distance: thinking, then braking" simulation show?
- For the reaction time the car keeps its full speed (yellow). Then the brakes give a steady retardation until it stops (red). Press Play and watch both on the road and on the v–t graph.
- Does JEE Main ask questions from Motion in a Straight Line?
- Yes. JEE Main asked 30 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
- Is this simulation free?
- Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Stopping distance and reaction time" in Motion in a Straight Line (Class 11 Physics).
Embed this simulation
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