Braking Distance Factors

Steps:

• Define braking distance as the distance traveled while brakes slow the car to a stop.
• Identify key physics: depends on initial speed (higher speed increases distance via kinetic energy) and road friction (wetter roads reduce grip).
• Note tiredness affects reaction time, impacting thinking distance, not braking.
• Evaluate options: C matches speed and road condition as braking factors, excluding tiredness.

Why C is correct:

• Braking distance follows the formula d = v²/(2μg), where v is speed and μ is friction coefficient (road condition), excluding driver alertness.

Why the others are wrong:

• A: Wrongly excludes road condition, which affects friction.
• B: Wrongly excludes speed, the primary factor in kinetic energy dissipation.
• D: Wrongly excludes speed while including tiredness, which influences thinking distance only.

Final answer: C