If a child ran into the road 65-70 feet ahead of your vehicle, what is the highest speed from which you could stop before hitting him?

the speed of the vehicle should be 57.68 ft/s

Step-by-step explanation:

Given:

child is running ahead of vehicle by 65-70 ft.

we are given with range of stopping distance

The stopping distance is calculated by

where

μ = 0.8, coefficient of static friction

g =  32ft/s²

now,

at  d = 65 ft.

v = 7.155√(65) = 57.68 ft/s

at  d = 70 ft.

v = 7.155√(70) = 59.86 ft/s

To be safe, the speed of the vehicle should be 57.68 ft/s