Goal of Class Activity
The goal of the class activity was to study Newton’s Second Law of force and motion. Newton’s Second Law recognizes that there is a relationship between mass and acceleration, and that the product of mass and acceleration is force.
The Experiment
The experiment was to demonstrate a proof of Newton’s Second Law. This was done by fixing force, and then varying mass and acceleration, and then fixing mass, and varying force and acceleration.
Introduction
For this experiment, we used the Lego Mindstorm motor. This apparatus has a pulley on which weights can be attached, and it is hooked up to a computer that can record measurements. In this experiment, we tried using different weights to represent varying mass, and we used the computer to manipulate the force on the pulley so we could vary force.
Methods
First, we did an experiment varying mass, but keeping force constant, and seeing the effect on acceleration. We kept the force at 75, and tried masses at the following weights: 0.10, 0.08, 0.06, 0.04, and 0.02 KG. Then we calculated the acceleration (RPM/S). Finally, after measuring the height in meters, which was 0.37, we calculated potential energy by multiplying mass by acceleration by height.
Next, we varied force, but kept mass constant at 0.18 KG. Force was set at 30, 40, 50, 60, and 75, and acceleration was calculated. Again, we calculated potential energy by multiplying mass by acceleration by height. Finally, we made charts to visualize the relationship between acceleration, force, and mass.
Sample Calculation
For the first part of the experiment, a sample calculation is given here. This is where force was set at 75, and mass was varied. In one case, mass was set at 0.10 KG, so for this case, the calculation of acceleration was done by the computer, which was 14.25. Then, potential energy was calculated to be 0.10 * 14.25 * 0.37 (height) = 0.63.
For the second part of the experiment, a sample calculation is given here. This is where mass was set at 0.18 KG, and force was varied. At the force of 75, the acceleration was calculated by the computer to be 33.10. Next, potential energy was calculated to be 0.18 * 33.10 * 0.37 = 2.20.
Results
First, I will report the results of the first part of the experiment, where force was fixed at 75. Below is the data table:
These data are charted in the figure below.
As can be seen by the figure, at low levels of mass, acceleration was high. This means that there was a strong, negative correlation between acceleration and mass at a fixed level of force.
Next, I will report the results of the second part of the experiment, where mass was fixed at 0.18 KG.
These data are charted in the figure below.
With mass fixed, as force increased, acceleration increased. There was a strong, positive relationship between acceleration and force.
Conclusion
This experiment was a successful proof of Newton’s Second Law of Motion. It demonstrated the relationship between mass, force, and acceleration.