12. Train mass m = 784 m starts moving downhill and t = 50 s can reach speeds υ = 18 km / h. The drag coefficient is μ = 0,005, the slope φ = 0,005. Determine the average power of the locomotive, considering the drag force is proportional to the force of normal pressure.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)