Q.2.16. A tractor of weight 15,000N crosses a single span bridge of weight 8000N and of length 21.0m. The bridge span is supported half a meter from either end. The tractor’s front wheels take 1/3 of the total weight of the tractor, and the rear wheels are 3m behind the front wheels. Calculate the force on the bridge supports when the rear wheels are at the middle of the bridge span.