In the above table, the third point of period distance will be considered as a random error.
Aspect 2:
1. Calculating the period time:
TP = Number of Frequencies
Period Frequency
TP = 1
(30.0 + 0.5) s-1
TP = 0.0333s
EP = 0.0333s ( +0.5s-1 / 30.0s-1 )
EP = +0.0006s
2. Calculating the speed:
v = distance / time
= (0.016 + 0.001) m / (0.0333s + 0.0006) s
= 0.048048ms-1
Ev = 0.048048ms-1 (( + 0.0006s/0.0333s) + ( + 0.001m/0.016m))
Ev = 0.004ms-1
Aspect 3:
Table #2: Processed data of Period Time and distance of eight consecutive periods
Graph #1: Total Distance vs. Total time
Graph #2: Period Speed vs. Total Time
Slope of graph #1 (Distance vs. time graph):
Slope = (0.113m – 0.032m) / (0.233s – 0.067s) = 0.48795ms-1
Slope max = (0.130m – 0.015m) / (0.261s – 0.0339s) = 0.5064ms-1
Slope min. = (0.128m – 0.017m) / (0.271s – 0.0327s) = 0.4658ms-1
Error: max – min / 2
Em = (0.5064ms-1 – 0.4658ms-1) / 2
Em = 0.02ms-1
Conclusion and Evaluation
The aim of the experiment was to test how well a level air table can be used to simulate uniform motion. The puck was placed in an elastic launcher and launched on the air table while electric shocks measured the distance travelled. The puck travelled in a straight line, this is suggested by Graph #1 where a straight line is produced between total distance vs. total time. The second graph didn’t produce a complete horizontal line due to the random error that was found at the third period. The horizontal line tells that the puck was travelling at a constant speed and would have accomplished uniform motion. The slope of the graph was calculated and the average speed of the puck was found to be at 0.49 + 0.02ms-1 .
Although the lab was a success, there were problems found during the lab. One of them would be spinning of the puck when released from the launcher. The spinning was most likely caused because of an unequal force being applied on one side of the puck by elastic. This did not only cause the puck to travel in a curve line but also affected the measurement of the actual distance travelled by the puck during the designated amount of time.
There were not any other errors caused by the apparatus. It was stable enough for the experiment. Therefore, there is no need to change the apparatus if this experiment would be done again. However, some other materials could be used such as the mechanical device that distributes equal force to both sides of the puck and make the puck go straight. This will bring improvements to the accuracy of measurement.
