A freight train consists of 4 engines at the front, followed by 28 rail cars. Both the engines and rail cars have the same mass of 758,143 kilograms each. Each engine exerts the same force backward on the track to push the train forward. The total force of friction on the entire train is 801,647 Newtons and is evenly distributed among all of the cars and engines. Even with this friction present, the train engines are able to accelerate the train at 0.05 meters/second2. What is the magnitude of the force in Newtons in the coupling between the engine and the first rail car?

Awater balloon launcher uses an elastic band with a spring constant of 115 n/m to use thee launcher you stretch thee band back with a balloon n it the water balloons have a mass of 1.3 kg a) if you stretch the band by 0.8 m, what elastic force will the band exert? b) with the band stretched 0.8 m, how much elastic potential energy is stored in the spring? c) if you release the band, it pushes forward. what is the kinetic energy of the balloon when it reaches the natural length of the band? d) what is the speed of the balloon when it reaches the natural length of the band?