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Two automobiles both of which have the mass center located midway between the front and rear axles,are identical except that one is front-wheel-drive and the other is rear-wheel-drive.The cars are driven at constant speed at ramps of various inclinations.The question is to judge which car could climb the ramp of higher inclination angle from a theoretical point of view.

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My idea was that the front wheel drive would be more effective if more weight acts on the front wheel.But in this case the center of gravity is midway between the rear and front wheel axles .I couldn't see how I can approach this problem.Any ideas?Thanks.

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    $\begingroup$ surely as you change the angle the CoG effectively moves towards the rear? Which means the front wheels are unloaded compared to the rear... $\endgroup$ – Solar Mike Sep 23 '17 at 11:41
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The rear-driven car is able to climb higher inclination.

Rational:

  • Where is the engine and the weight has for sure an impact, but it is not related with rear or front driven car: You have rear-driven cars with engine in the front and reverse. Additionally, you specify that the center of gravity is in the same place (center), so the place of the engine has no impact.
  • However, if you consider the forces acting on the car, the gravity will lower the weight component on the front and increase the weight component to the rear. This increase the capacity of a rear-driven car to climb.

Note: Consider however, that rear-driven cars will have lower direction control while climbing, and for this reason, they might have big issues in climbing icy roads.

Note 2: Driving a front-wheel-driven backward allows to climb higher inclinations than forward. But probably not something to try on the highway.

Note 3: The ideal situation for climbing strong inclinations is the rear-wheel-driven car with rear direction (you do not have the problem of control). You may find several construction machines designed in this way, but it is not practical (difficult to drive) at high speed, and thus not used for cars.

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