What We Did:

In class we constructed the NXT System and gave our little robot directions to move forward. We repeated this process three times, each time using different power on the wheels. We measured the distance the robot moved for each power usage and then compared to the actual distance it moved that we got from the NXT program. Also, we recorded the number of turns the wheels did  and the time for each power usage.

Results:

From the table we can get the results we acquired for the experiments we carried out.

How are degrees and number of turns linked?

We know that each turn is 360 degrees, which means that the number of turns represents how many times the wheels have turned 360 degrees.

How is the distance related to the number of turns?

The distance is directly proportional to the number of turns of the wheels;the more(or less) the turns, the more(or less) will be the distance covered.

In fact by knowing this we can even find a formula for the two variables. That formula is Distance=(1.8*10^-4)*numberof turns

Recorded Distance Vs Actual Distance:

From the table we can clearly see that the distance we recorded was not the same as the actual distance. From our results we can calculate the percentage error that our measurements had. When the power was set at 75, the percentage error was 4.48%. When the power was 85 the percentage error was 2.72%. Finally, when the power was set at 100 the percentage error was 3.48%. We can understand that our measurements were off by approximately 3.5% on average from the actual measurements. The cause for the discrepancy we recorded is three-fold. When the car was moving, it would move  slightly after stopping due to inertia. As a result, we had to estimate the spot it stopped at and apparently our estimates were not 100% accurate. The other factor that played a role in the discrepancies was that we were using a ruler, which has a set limit of accuracy and that limited our estimates further. Finally, the fact that the wheels were not turning at the same rate(the table shows that the degrees varied with each wheel) indicates that the car was not moving in a straight line. Since we were recording the straight line that the car moved in, we did not get the actual distance, which in this case was a sort of a hypotenuse.(while our line was the line opposite the hypotenuse that is smaller than the hypotenuse.) This fact also explains why our results were always less than the actual distance. If you are finding it hard to visualize the problem then the amazingly cool represantation that i created using paint might help.

Ultimately, it was another fun class that taught us again that computers are better than us.