The maximum rimpull in the first gear of a tractor while towing a load is 6300 kg. The tractor weighs 12.5 tonnes and is operating along a 2 percent upgrade and the rolling resistance is 45 kg/tonne. Pull available for towing the load is A. 3425 kg B. 5515 kg C. 4350 kg D. 2975 kg

The correct answer is B. 5515 kg.

The maximum rimpull in the first gear of a tractor while towing a load is 6300 kg. This means that the tractor can pull a load of up to 6300 kg up a flat surface. However, the tractor is operating along a 2 percent upgrade, which means that it is actually pulling against a force of 200 kg. The rolling resistance is 45 kg/tonne, so the tractor is also pulling against a force of 562.5 kg due to rolling resistance. Therefore, the total pull available for towing the load is 6300 – 200 – 562.5 = 5515 kg.

Here is a breakdown of each option:

• Option A: 3425 kg. This is the pull available for towing the load if there were no upgrade and no rolling resistance. However, there is an upgrade and rolling resistance, so this option is incorrect.
• Option B: 5515 kg. This is the correct answer. It is the pull available for towing the load after taking into account the upgrade and rolling resistance.
• Option C: 4350 kg. This is the pull available for towing the load if the upgrade were 1 percent instead of 2 percent. However, the upgrade is actually 2 percent, so this option is incorrect.
• Option D: 2975 kg. This is the pull available for towing the load if the rolling resistance were 30 kg/tonne instead of 45 kg/tonne. However, the rolling resistance is actually 45 kg/tonne, so this option is incorrect.