2. It is a car launcher.

3. The car goes into the two connect pieces. Then you pull the lever causing the gears to mesh. Then when you let go of the lever the car will role off causing motion.

4.  Wheel and axl  Lever. You push down the lever making the car and the other gears mesh.

5. It could be used as a motor because when you pull down the lever the wheels spin The motor in the back has a switch and that can be reversed and accelerated.

6. The input is when you put the car into the launcher and the output is when you release the car from the launcher.

7. 5:1