Dear sir/ma'am, I was watching a video of chapter Force and Laws of Motion, in that chapter there was a video (Engine Problem one video) in that video question was the same as my ncert science textbook (question no. 7 of the book). The question was as follows, A 8000 Kg engine pulls a train of 5 wagons, each of 2000 Kg, along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate : A. the net accelerating force; B.the acceleration of the train ; and C. the force of wagon 1non wagon 2. So, my droughts are that 1.In the video he did find the acceleration of the train(3.5 m/s2)but he excluded the mass of the train, and when I find the acceleration of the train including the mass of the train my answer was same as in the book(1.944 m/s2) So, why did he excluded the mass of train? 2.The third part of the question was to find the force of wagon 1 on wagon 2, he did find that also but in the book answer is different (15556).Why? Can I get a solution of this question? (all the parts)