The friction between a moving body and the ground slows the object down until it comes to a stop. A higher friction factor, such as you'd experience on rough roads, slows a body more quickly, and a lower factor, which oil or ice create, slow the object down more gradually. The higher an object's friction with the ground, the faster it must travel to fully decelerate over a fixed distance.

Multiply the road's friction factor by 2. For this example, imagine a road with a friction factor of 0.08  0.08 x 2 = 0.16.

Multiply this answer by standard gravity, which is a constant 9.81 Newtons per kilogram  0.16 x 9.81 = 1.5696.

Multiply the result by the distance that the body travels before stopping, measured in meters. It covers, for instance, 100 meters  1.5696 x 100 = 156.96.

Find the square root of this answer  156.96^0.5 = 12.53. This is the object's initial velocity, measured in meters per second.
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