Mechanical System Efficiency
Problem statement and restraints
Using fischertechnik parts, build a winch that can be used to lift around 100 grams of weight. Then, find the work done by the system, the power of the system, and the overall efficiency of the machine. You will need a multimeter to measure the voltage.
Calculations
After building our winch and getting the battery hooked up, we put a switch on to turn the power on and off. We attached a string to the winch and tied a string around it. With a permanent marker, we marked a starting and stopping place with 30 cm between the two. The 100 gram weight was tied to the end of the string and was lifted up slowly. As the weight was lifted up, the average voltage reading was .022 volts. Afterwards, we broke the circuit and measured the current of the machine which turned out to be 0.4 mA. The total time in seconds for the winch to lift the 100 g weight 30 cm was 38.4 seconds. The winch system did 0.030 J of work. The output power of the system was .001W while the input power was 0.008W. The precentage of efficiency ended up being 11.5%, which isn't too efficient.
Final product
Our final product wasn't as efficient as I would have liked it to have been. Everything worked, every part of the system was functional. The winch lifted the weight up pretty slow, but it had a lot of torque to get the job done.
Reflection
This was a fun project overall, it was helpful to work hands on with the fischertechnik parts and the multimeter. Even though I didn't get the most out of the project as I could of/would of liked to, I learned a few things. Maybe we could have raised the efficiency of the wench by having a different gear ratio. We could have also used a higher voltage battery to increase efficiency. Overall, this was a helpful project and I would love to do something similar again.