This week, we learned about Newton’s 2^nd Law of Motion:

The acceleration a of a body is parallel and directly proportional to the net force F and inversely proportional to the mass m, i.e., F = ma.

 

In this lab, we explored the law of conservation of energy, Velocity and Acceleration and also Power. We used the Lego Mindstorm motor to lift weights with a pulley. The control page shown on the left is a photo of the command center for the motor used. The motor lifted the weights to a fixed height (km) and our control page documented how long (Time measured in s) it took for the motor (set at a specific Power Level) to lift the different weights (Mass  measured in kg), the motor’s Speed (RPM), the Acceleration (rpm/s), the Battery Discharge (mV), and its Power (different from power Level).

 

In our first trial, the Power Level as well as the height were the controlled variables; Power Level at 75 units and height at 0.3 km. We conducted this experiment 5 times each time changing the mass to a different  weight. We also took into account that this experiment is administered in a gravity friendly environment therefore, we added the standard value of gravitational acceleration at sea level on Earth (9.8 m/s²).

 

 

 

With this chart, I examined the negative relationship between Acceleration and Mass (kg). You can see that as the Mass increases, the Acceleration decreases. This holds true to Newton’s Law of Motion F=m*a

 

 

Using the same chart, I also examined the relationship between Battery Discharge and Mass (kg). In this graph, the correlation is not as easily detectable.  Though  it seems like a positive one, the correlation coefficient is very weak (around +0.3).  It is hard to read a graph that could either be showing error in      calculations or could simply be telling us that there is not much of a correlation between Battery Discharge and Mass.

 

In our second trial, the Mass was fixed to 0.05 kg throughout all four experiments.  The height (0.3 km) and gravitational pull ((9.8 m/s²) remained the same, resulting in the Gravitational potential energy (m*g*h) staying at a constant 0.147 (kg m/s²). We began with a Power Level of 25 and increased it in increments of 25 per experiment.

 

 

 

 

 

 

I looked at the relationship between Power and Power Level using the second chart and realized that they have a positive correlation. What this means is that the higher the Power, the higher the Power Level.

 

 

 

 

 

Finally, I examined the relationship between Acceleration and Power Level; which was a positive one. The chart reads that the higher the Power Level, the higher the Acceleration.

 

 

 

I think that this lab was a more hands on way of learning about Newton’s 2nd Law of Motion. While conducting these trials, I hand recorded all of the data just in case anything went wrong with our experiments. We made a few mistakes with the distance but because we wrote down our data by hand, we were able to catch the discrepancies and omit them from our final data charts.