The past week, in the freshman seminar class, we performed multiple experiments with a lego powered pulley. Using mass and power, we see the acceleration and also time it took for the pulley to complete its work. We also looked at battery discharge with other factors. We had a setup of a Lego mindstorm with the motor connected to port A. It has a attached lego wheel rim part. It had a string attached to the wheel and it goes up to a pulley. Then we have removable weights that goes on a base with a hook. We then proceed to test the program that we downloaded, to make sure  our lego mindstorm is working. After that we proceed to change variables, like the  power and the weights, as  they should change the results we get each time we run the program. The more or less power the motor put to pull the fixed weight up. The more or less weight but power doesn’t change. We saw the time it took each different set. We also took in the power discharge or remaining power left in the battery.

To begin the weight was first set to .25 kg. We ran the program and pressed the stop button when the mass was at the top. We then reset and lowered the mass to .19 kg and then .13 kg after that. I expected that the acceleration would increase because there was less mass. As expected the acceleration increases each time we lower the mass. Acceleration is measured in rpm/s or rotation per minute/seconds^2. The acceleration went from 40 rpm/s^2 to 44 rpm/s^2 to 50 rpm/s^2. However we also expected the opposite for potential energy because potential energy is mass x acceleration by gravity x height. Since height remains at .25 meters and acceleration caused by gravity is 9.8 meters/second^2, and mass is the only one changing and its decreasing, its expected that it would decrease, and the result prove that it was going down. The potential energy started from .61 joules to .46 joules and to .31 joules.

The next thing that we also measured was power level and power discharge. As we increased the power level or power used by the lego mindstorm the power discharge would increase. When we used a power level of 50 , the battery discharge was 41 mV. Then at 75 , the battery discharge was 55 mV, Lastly, at 90 , the battery discharge was 83 mV.

Here is the Data:

We looked at the Newton’s 2nd law; Does acceleration change depending on mass?As Acceleration decreases, mass increases. This therefore proves the 2nd law F=ma where F stays constants and mass increases, the acceleration must decrease to balance the mass increase.Another question was that does acceleration change depending on power level. Since F is increasing and mass remains constant, acceleration must increase to balance out.

We then looked at the Law of Conservation of energy.Since the energy is turn into potential to the mass, as mass increase, the power discharge should increase as well. That concludes my experiment with the pulley and mass with the lego motor.