Average Mass of Each of the Spheres Used Average Height of Each Sphere’s First Bounce When Dropped from Two Metres Conclusion: The efficiency of the golf ball is 72%, which is the most efficient amongst the three balls, the efficiency of the tennis ball is 54%, and the field hockey ball is 27% efficient making it the least efficient amongst the three. The hypothesis was correct about the order in which the efficiency should be in.
The size and mass may possibly have an effect on how efficient each ball each. Another factor that is also very important, but however not considered in the analysis is the material that each ball is made of.The amount of elastic energy of each ball was not considered in the experiment, and should be included.
To find out how much the elastic energy of a sphere affects its efficiency, one has to find out the relationship between the elastic energy, the mass and the height of the ball and calculate to see how much difference this will make, and how important the elastic energy of a sphere is. An important error is that the height of each ball’s bounce may not be entirely accurate since the ability of the human eyes is limited and can’t tell exactly how many metres the ball bounced. To minimize the effect of this error, several trials and the results of many people can be combined, and then the average amongst the results can be calculated.
The electromotive force that we should have obtained is 12.0 Volts. (We know this because we measured the potential difference when it was on Open Circuit before we began the experiment). However, the value we extrapolated from the graph is 10.136 Volts which is quite different from the hypothetical value. In conclusion, this experiment turned out to be not a very successful lab.
Internal resistance was rather different than from what we had first expected.Internal resistance was substantially lower than it should been. The total resistance of the circuit was not solely based on the variable resistance of the Rheostat itself but included its initial resistance.
The Power Supply and the Rheostat (Variable Resistor) were the main sources of internal resistance. The Ammeter and Wires could only be accounted for marginal internal resistance. Yet 10.136 Volts is still too low a value to be correctly interpreted. For those reasons, it means that 1.864 Volts are missing somewhere in the circuit.
We were not able to get a theoretical literature value. There are three reasons for that. Firstly, even if we lower the resistance of the Rheostat, it will still have some resistance and hence we have to take this into consideration.
Second reason is the thermal factor. When we increased the resistance of the Resistor, the current got lower and the Resistor got hotter. In other words, increasing resistance caused increasing temperature and then more increasing resistance. The last reason is that the clip bridging the main wire to the Resistor was not a good conductor. The clip that we attached to the Resistor was deemed to be another resistor rather than a conductor. These three factors affected our final value and hence it turned out that the EMF from our graph did not meet with the hypothetical value.
In order to get more accurate data, we first need to change the resistor in the Rheostat for another conductor such as plain wire. We should also have considered the thermal factor and should maintain constant temperature for the Resistor. There should be intervals between trials for cooling down. In addition, we need to use more conductive metal for the clip such as Aluminum or even Gold.