A car travelling at 108 km/h brakes with a constant deceleration of 5 m/s^2. What is the braking distance?
Answer and explanation
Correct answer: C. 90 m
- Step 1: The speed is 30 m/s.
- Step 2: Braking distance = v^2 / (2a) = 900 / 10 = 90 m.
Answer
90 m.
Why not the others: The factor 2 in the denominator matters; leaving it out doubles the distance, and dividing the speed by 2a instead of squaring it gives far too little.
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