In small groups in class, we performed a classical physics experiment, which involved mass and pulley, to test gravitational potential energy and theory of conservation of energy. Our version of the experiment used a robot to apply the force on the mass. The robot with its sophisticated sensors allowed us to record not only the force but also battery discharge (measure of the potential energy stored in the battery converted into mechanical energy), power with which the mass was pulled, velocity of the mass, and time the mass was pulled. Analyzing the data and applying formulas (such as Ep=mgh, Power=Energy/Time, and a=V/t), we constructed the graphs to see if the correlations between the variables (acceleration vs. mass, battery discharge vs. mass, power level vs. acceleration, power level vs. power), which we found, support the theory.

The first graph shows the correlation between mass and acceleration given a constant force. The coefficient of correlation  is 0.85, which supports the theory that there is a linear relationship between the two variables (F=ma, given the constant force, we would expect a linear relationship between mass and acceleration).

The second graph compares the power level input and actual power, which we computed as Power=Energy/Time. Given the constant mass, we have a linear relationship with the coefficient of correlation of 0.81 between power and power level, which is the result compatible with the theory. As expected the power increases as we increase power level.

The third graph shows the battery discharge vs. mass, given the fixed power level. Despite of the inconsistency of the data due to the specificity of the robot’s computations of the battery discharge, we still have a coefficient of correlation of 0.44, which supports our theory that given the constant power level, we have a linear relationship between battery discharge (indicator of energy used) and mass (E=mgh, for constant height, we would expect an increase in energy as we increase the mass).

The fourth graph shows the relationship between power level and acceleration, given the constant mass. The coefficient of correlation between the two variables is 0.88, which supports the theory that there is a linear relationship between the power level and acceleration for the fixed mass (P=Fv=m*g*v=m*g*a*t, given the constant mass, an increase in power leads to an increase in velocity, which is obtained through an increase in acceleration).