In our second experiment using the NXT Robotics program, we explored the concepts that make up the fundamentals of Isaac Newton’s Laws of Motion. As we saw in class, these laws have been proven time and again by scientists throughout the ages. Newton’s first law and his second are the ones we primarily focused on for our research in class, but for the sake of this blog and continuity, I will provide a list of all three:
Newton’s First Law of Motion:
| I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. |
Newton’s Second Law of Motion:
| II. The relationship between an object’s mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector. |
Newton’s Third Law of Motion:
| III. For every action there is an equal and opposite reaction. |
Using only the battery and motor from the original Mindstorm robot, we connected these to a platform which had a raised pulley. We attached the motor to the string around the pulley, which had a weight attached to its opposite end hanging over the pulley. In this way, we constructed a machine that would utilize Newton’s laws. Mostly, we were using the machine to get quantitative data to support Newton’s second law. Although our group ran out of time to do the experiement completely, and we managed to achieve some questionable data through our own measuring errors, I believe that the data we did get can support Newton’s laws, although our data cannot be considered totally accurate.
In the first part of the experiment, we were required to see the effects when we kept the motor’s power level at a constant (75) and changed the mass attached to the pulley. In the second, we changed the power levels, but used a constant mass. In this way, we were able to see the effects, as shown in the following chart pulled from NXT and placed into an Excel spreadsheet:
Having collected our data, we used the wonders of Excel to create charts to show the results visually. (I can’t for the life of me figure out how to take my graphs from the Excel sheet and insert them into this post with correct formatting, so props to A. Bray for providing the following!)
From this, we determined that our data was probably not 100% accurate, or it would follow a trend more closely. Taking this into consideration, I still think our data proves Newton’s second law. The more power one has, the greater the acceleration of the object. The greater the mass at a constant power level, the more power is required, and of course, the higher the power level used, the higher the actual power (work/time). If we had had a little more time last class, we likely would have achieved better results and come up with more conclusive evidence.
http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html