A pulley is fitted to the first driven shaft of compund gear train. Last driven shaft of gear train(gear 8) is fitted to the 12V DC generator (6W).Now to the rope extension at the one end of the pulley a mass of 10kg is added. 
The whole assembly is placed at an height of 2m from ground. The pulley is of 0.1m diameter. 

The compound gear train consists of 8 spur gears of 2mm module having teeths Gear1 = 120, Gear2 = 110, Gear3 = 100, Gear4 = 40, Gear5 = 24, Gear6 = 22, Gear7 = 18, Gear8 = 18. 

Gear 1&5, 2&6, 3&7, 4&8 are engaging. The gears 2&5, 3&6, 4&7 are on same shaft(concentric gears). Pulley and Gear 1 are on same shaft. DC generator and gear 8 are on same shaft. See fig. below.

All gears have Module = 2mm & involute tooth profile with pressure angle 20 deg. Space width of gears = 18mm.

I need to find the speed (RPM) at which Gear 1 i.e of 120 teeth and the pulley rotates as the mass of 10kg comes down due to gravity.

I know to solve the problem is a lot to ask but some info on how to solve would be helpful. 

Again I am not asking to solve the problem and give me the answer. I have already solved it. I am just looking for different ways of solving it. 

**This is what i exactly need to know:
I found that the mass when added to the pulley ropes with a load on generator, falls down slower with a constant velocity as compared to free fall condition where it falls with acceleration due to gravity. How is that possible and what are all the factors contributing to this change in type of motion?** 

**This isnt my homework. Its for a hobby project of mine.**

Thank you.[![Gear train arrangement](https://i.stack.imgur.com/rytwO.jpg)](https://i.stack.imgur.com/rytwO.jpg)