This key facts covers Factors Affecting BRAKING Distance within Stopping Distances for GCSE Physics. Revise Stopping Distances in Forces for GCSE Physics with 13 exam-style questions and 5 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 4 of 12 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 4 of 12
Practice
13 questions
Recall
5 flashcards
🚗 Factors Affecting BRAKING Distance
Braking distance depends on:
- Speed — braking distance is proportional to v² (double speed = 4× distance)
- Braking force — stronger brakes = shorter distance
- Mass — heavier vehicle = longer to stop
Adverse conditions:
- Wet roads — less friction, longer braking
- Icy roads — much less friction, MUCH longer braking
- Worn tyres — less grip
- Worn brakes — less braking force
- Overloaded vehicle — more mass to stop
Why braking distance is proportional to v²: The brakes must transfer ALL the kinetic energy. Since KE = ½mv², double speed means 4× energy to transfer!
Quick Check: A driver's reaction time is 0.7 s. The car travels at 20 m/s. Calculate the thinking distance.
Thinking distance = speed × reaction time = 20 × 0.7 = 14 m. This is the distance the car travels before the brakes are even applied.