Answer:
The acceleration is
![a = 0.889 \ m/s^2](https://img.qammunity.org/2021/formulas/physics/college/cytqnpk7mrqvgism7p9d4ist7fe54km9w8.png)
Step-by-step explanation:
From the question we are told that
The mass of the engine is
The mass of each Boxcar is
![m_b = 1500 \ kg](https://img.qammunity.org/2021/formulas/physics/college/ouoiart80wq6kxjmnulskgu569a6l3h68n.png)
The tension between the locomotive and boxcar A is
![T = 4000 \ N](https://img.qammunity.org/2021/formulas/physics/college/gryd5dq46vv76eirbi9kpocoeh3bx83ofk.png)
Generally the tension between the locomotive and boxcar A is equivalent to the net force propelling the box cars so the tension is mathematically represented as
![T = F = M* a](https://img.qammunity.org/2021/formulas/physics/college/4xnl613kofbrhgjpzh6bn89xm3yc7244jx.png)
Here M is the mass of the three box cars
=>
![4000= (3 * 1500)* a](https://img.qammunity.org/2021/formulas/physics/college/ppj76n3i1a2rczj7c6ctl11g724sitejsk.png)
=>
![a = 0.889 \ m/s^2](https://img.qammunity.org/2021/formulas/physics/college/cytqnpk7mrqvgism7p9d4ist7fe54km9w8.png)