To collect the data we ;et the dynamics trolley off and when it broke the light beam of the light gate then the QED would work out the average speed. The results are in the table below.
Results
I took 3 readings so that I could get an average of the 3 and, so if there was an outlier I could use the other readings as an average. The reading in red was an outlier it could have been of us setting that reading up wrong or could have been us letting the trolley off from the wrong distance, therefore it gained more speed than the other times. We had one 2 dependant variables, the distance and the height because we controlled each of them during the experiment. The equation to find the average is you add up the 3 reading and then divide by 3. The other equation the light gate would have used is Speed=Distance / Time.
Interpretation
The graphs that I have made, without the outlier, there is a very slight linear correlation. It is as the height increases, the average speed will increase. This is because the kinetic energy in the trolley increase as it moves quicker and quicker. Eventually the graph will level off because the friction will bring it to a stop after a while. The error bar would be 1mm for the height and for the average speed it would be 0.01 m/s of error because it is the smallest unit possible for this experiment.
Evaluation
I think that we used we used the right equipment and it gave us a very accurate result, but there was a chance of human error, as there is with every experiment done by a human. If we used a machine there still would have been a chance of mechanical error.
Our results show use that we did a fair and well conducted experiment it also shows us that we were consistent, except the when the QED showed us that we have a speed of 19.531. this could have been human error or a fault with the QED and light gate.
To improve the experiment we could have used a machine to adjust the height because there could have been a error of 0.1cm. The error bar shows this on the graph. A machine would have been programmed to do it accurately. This is caused by human error.
