Answer:
The value is [tex]d = 161 \ ft[/tex]
Explanation:
From the question we are told that
The gradient is G = 2% = 0.02
The initial speed of the vehicle is u = 40 mph
Generally the breaking speed is mathematically represented as
[tex]d = \frac{u^2}{30 [\frac{a}{g} - G ]}[/tex]
Here [tex]\frac{a}{g}[/tex] is equal to longitudinal friction coefficient which has a value of
[tex]\frac{a}{g} = 0.35[/tex]
So
[tex]d = \frac{40^2}{30 [0.35 - 0.02 ]}[/tex]
=> [tex]d = 161 \ ft[/tex]
