Fundamentals of Transportation/Grade/Additional Problems

Additional Questions

 * 1) What is maximum grade a vehicle can travel, what effects it? Explain how to find maximum grade at a given speed.  Explain what each variable means and how it contributes to figuring max grade.
 * 2) Why are $$A$$ and $$C_D$$ the only things need to calculate air resistance.  → Because it is a crude approximation of aerodynamics.  Real aerodynamics are of course  complicated, but the additional detail does not sufficiently improve accuracy.
 * 3) If there were no heavy vehicles, would planners design roads with steeper grades? → Yes, they should. There has been discussion for a number of years for separate car and truck highways, since car-only highways would be cheaper and truck-only highways could avoid congestion.  However additional rights of way would be required
 * 4) Define rolling resistance. Why is rolling resistance different for cars and trucks?   What is the difference between rolling resistance and maximum grade?
 * 5) What is the relationship between available power and nominal power? Why do trucks use more of their nominal power than cars.
 * 6) What is the mass/power ratio used for?
 * 7) What happens if air resistance is larger than tractive effort force.
 * 8) What is maximum grade a road can have?
 * 9) What forces affect vehicle motion?
 * 10) What are two relevant parameters for passenger car, type $$P$$?
 * 11) Define $$F_r$$, $$F_a$$, $$F_t$$, $$F_g$$.
 * 12) If given a grade of 3%, should you use 0.03 or 3 in the equation?
 * 13) How does coefficient of rolling resistance vary between vehicles.
 * 14) What kind of safety factors are in these equations.

/Additional Problems