Mechanics Question. IV :) A breakdown van of mass 2000 kg is towing a car of mass 1200 kg along a straight horizontal road. The two vehicles are joined by a tow bar which remains parallel to the road. The van and the car experience constant resistances to motion of magnitudes 800 N and 240 N respectively. There is a constant driving force acting on the van of 2320 N. Find (a) the magnitude of the acceleration of the van and the car, (b) the tension in the tow bar. The two vehicles come to a hill inclined at an angle α to the horizontal, where sin αlpha= 1/20 . The driving force and the resistances to the motion are unchanged. (c) Find the magnitude of the acceleration of the van and the car as they move up the hill and state whether their speed increases or decreases. --- Hey... I get the first 2 questions... with the answers of 0.4m/s and 720. however (c) .. i dont really get... i would think of using the sin 1/20 in my answer [along with F=ma where m is 3200 (sum of the two cars' masses) ]... but the model answer contradicts this... they dont use sin or cos... could someone please help me out on this one... :) Thanks a lot.