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
Should the mass of engine be included in finding answers or not.
Pls explain also

Yes it should also be included as if we try to ask only the force required to move only the engine then we will take the engine mass and it's acc.
So if we want to calculate the force required to move the engine with the 5 wagons ,then we will required to take the total mass to be
= Engine mass + mass of one wagon*5 * acc. produced .