When the Crampton coal-fired train engine was built in 1852, its mass was 48.3 t (1.0 t = 1.0 x 10^3 kg) and its force capability was rated at 22.4 kN. Assuming it was pulling train cars whose total mass doubled its own mass and the total friction on the engine and cars was 10.1 kN, what was the magnitude of the acceleration of the train? What I have: (not sure if it's right though) m = 48.3 t = (48.3 x 10^3 kg) x 3 = 144.9 x 10^3 kg net force = 22.4kN - 10.1 kN = 12.3 kN = 12300 N acceleration = ? acceleration = net force / mass = 12300 N / 144.9 x 10^3 kg acceleration = 0.0849 m/s^2 acceleration = 8.49 x 10^3 kg Is this right? because 0.0849 m/s^2 doesn't seem very reasonable to me. If it's wrong, could someone please help?