When an agricultural tractor climbs an uphill slope while exerting a heavy drawbar pull, which of the following mechanical effects occur?
Options:
(A) Dynamic normal load on the rear drive axle increases due to both the gravity slope component and drawbar pull weight transfer.
(B) Dynamic load on the front steering axle decreases, reducing steering response and increasing the hazard of rearward tipping.
(C) Rolling resistance of the front tires decreases due to the reduced front vertical ground reaction.
(D) The center of gravity coordinates shift physically relative to the tractor chassis casting.
Answer Key:
A, B, C
Step-by-Step Solution & Explanation
• Uphill slope angle and drawbar moment combine to unload front axle and load rear axle (A and B are correct).
• Reduced front vertical reaction directly reduces front wheel rolling resistance ($R_r = \mu W_f$) (C is correct).
• The center of gravity is an intrinsic physical property fixed relative to the tractor metal chassis (D is false).