Answer:
3.
Explanation:
We start calcualting the factor for heavy-vehicle, that is,
for rolling terrain, so, replacing,
We calculate the number of lanes by using the relation as follow:
In this way the necessary number of lanes is 3.
Note: To calculate 
you need to consult the Exhibit 23-2
in 'Highway capacity Manual' for 55mph and the LOS D criteria.
I attached a photo that explains and gives the answer to your questions. Had to add a border because the whole picture didn’t fit.
Answer:
The answer to the question is 514.17 lbf
Explanation:
Volume of cylindrical tank = πr²h = 3.92699 ft³
Weight of tank = 125 lb
Specific weight of content = 66.4 lb/ft³
Mass of content = 66.4×3.92699 = 260.752 lb
Total mass = 260.752 + 125 = 385.75 lb = 174.97 kg
=Weight = mass * acceleration = 174.97 *9.81 = 1716.497 N
To have an acceleration of 10.7 ft/s² = 3.261 m/s²
we have F = m*a = 174.97*(9.81+3.261) = 2287.15 N = 514.17 lbf
