Question

Part B onlyThe braking distance d, in meters, of a vehicle traveling at a velocity v, in meters per second, is given by the formula

Answer 1

Answer:

340 feet

Explanation:

The braking distance​ d, in​ meters, of a vehicle traveling at a velocity​ v, in meters per​ second, is given by the formula:

$d=\frac{v^2}{2\mu g}$

Part B

Given:

• v =68 mi/hr

,

• μ = 0.45

,

• g = 9.8 m/s²

First, convert the velocity, v from miles per hour to meters per second.

• 1 miles = 1609.34 meters

,

• 1 hour = 3600 seconds

$68\frac{miles}{hour}=68\times\frac{1609.34}{3600}\frac{meters}{seconds}=30.40\text{ meters/seconds}$

Substitute v=30.40 m/s into the formula.

$\begin{gathered} d=\frac{30.40^2}{2\times0.45\times9.8} \\ d=104.78\text{ meters} \end{gathered}$

Finally, convert the result to feet.

$\begin{gathered} 1\text{ meter}\approx3.28\text{ feet} \\ \implies104.78\text{ meters}=104.78\times3.28\text{ feet} \\ =343.6784\text{ feet} \\ \approx340\text{ feet \lparen rounded to the nearest ten\rparen} \end{gathered}$

The braking distance is about 340 feet.