Hi all, Another teaser that I have been attempting is the following: A Locomotive (A) pulls two tracks (B) and (C). The masses of A,B & C are 80, 25 and 20 tonne respectively. The train starts from rest and accelerates uniformally to cover 2KM in 8 minutes. Assume the resistance to motion of the locomotive and the trucks is 200N/tonne 1. Calculate the tractive effort developed by the locomotive A. I have used the formula: Tractive Effort = Total resistance to motion (R) + Mass x Acceleration. The total resistance to motion is 200/N tonne x (80+25+20) = 25KN The mass is 125 Tonne The acceleration I have as 0.01736111 m/s using s=ut+1/2at^2. Therefore I have the tractive effort as 27.17K Newtons. Is this right??? 2. Calculate the draw-bar pull between A and B 3. Calculate the draw bar pull between B & C I am struggling with 2 and 3. Could anyone give me any pointers??