QuestionAugust 17, 2025

What is the maximum speed you can be traveling to stop before hitting a child that runs into the street 60-65 feet ahead of your car? Choose one 20 mph 30 mph 40 mph 50 mph

What is the maximum speed you can be traveling to stop before hitting a child that runs into the street 60-65 feet ahead of your car? Choose one 20 mph 30 mph 40 mph 50 mph
What is the maximum speed you can be traveling to stop before hitting a
child that runs into the street 60-65 feet ahead of your car?
Choose one
20 mph
30 mph
40 mph
50 mph

Solution
4.0(215 votes)

Answer

30 mph Explanation 1. Determine Reaction Distance Average reaction time is about 1.5 seconds. Convert speed from mph to feet per second using **v_{fps} = v_{mph} \times \frac{5280}{3600}**. 2. Calculate Braking Distance Use the formula **d = \frac{v^2}{2g\mu}**, where g = 32.2 \, \text{ft/s}^2 and \mu \approx 0.7 for dry pavement. 3. Total Stopping Distance Add reaction distance and braking distance. Compare with 60-65 feet.

Explanation

1. Determine Reaction Distance<br /> Average reaction time is about 1.5 seconds. Convert speed from mph to feet per second using **$v_{fps} = v_{mph} \times \frac{5280}{3600}$**.<br />2. Calculate Braking Distance<br /> Use the formula **$d = \frac{v^2}{2g\mu}$**, where $g = 32.2 \, \text{ft/s}^2$ and $\mu \approx 0.7$ for dry pavement.<br />3. Total Stopping Distance<br /> Add reaction distance and braking distance. Compare with 60-65 feet.
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