Respuesta :
The average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is 78.43 ft.
The given parameters:
- Speed of Mark, v = 40 mph
- Drag factor, F = 0.85
- Working efficiency of the brake, n = 80%
The average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is calculated as follows;
[tex]v = \sqrt{30 D fn} \\\\40 = \sqrt{30 \times D \times 0.85 \times 0.8} \\\\40 = \sqrt{20.4 D} \\\\40^2 = 20.4D\\\\1600 = 20.4 D\\\\D = \frac{1600}{20.4} \\\\D = 78.43 \ ft[/tex]
Thus, the average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is 78.43 ft.
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