Afreight train consists of two 9.00 ✕ 105 kg engines and 44 cars with average masses of 3.00 ✕ 105 kg. (a) what force (in n) must each engine exert backward on the track to accelerate the train at a rate of 6.00 ✕ 10−2 m/s2 if the force of friction is 7.50 ✕ 105 n, assuming the engines exert identical forces? this is not a large frictional force for such a massive system. rolling friction for trains is small, and consequently trains are very energy-efficient transportation systems. (enter the magnitude.) 54409 incorrect: your answer is incorrect. n (b) what is the magnitude of the force (in n) in the coupling between the 37th and 38th cars (this is the force each exerts on the other), assuming all cars have the same mass and that friction is evenly distributed among all of the cars and engines? (assume both engines are at the front of the train.)