Preliminary Test:
I have tried to set the height of 1M, I think this is the best height. Then I released the ball from 1M high and take the reading where the ball reach. After that, release the ball on the height where the last reading I recorded and keep on repeat. I have practised a few times before I started and I found that this is quite a good method to do this experiment and here is the result for my preliminary test:
From the result I get, I think I will use this method for this experimenta and I can predict that the graph will be direct proportion, that means the energy lost is lost by proportion and I predicted that the graph will be like that:
Method
First, I need the following equipment: a bouncing ball, a retort stand and a 1m long ruler. I will start the test from 1M high.
Then hold the ruler vertically by the retort stand. Before I start, I will practice for few times to make sure that the experiment is more accurate. After that, hold up the ball in front of the ruler and ready to start. Then release the ball from 1M high and bounce upward, immediately take the reading where the ball reach. After that, release the ball on the height where the last reading I recorded. And repeat this procedure for 10 times. This experiment is very safe, but something I need to notice is, I have to be careful not to knock down the retort stand.
Fair test
Before I start the experiment, I should practice for few times, to make sure that the experiment is more accurate. I will measure from the bottom of the ball to the surface, this will have a better result and more accurate. To have a better result, I preferred to start bouncing from 1m, because the lower you bounce, the more errors you have. I think I will do this test to on a table, because it is easier to measure than on the floor. To let the result more accurate, I will make sure that the surface will not change and I will take at least 10 readings to be able to plot the graph.
Obtaining evidence
It is very difficult to take the reading, so that I have done it for 5 times for each height and take the average.
Here is the results that I got:
Analyzing
I have plotted 2 graphs on the next page. From the first graph, it shows that the ball is kept on losing its energy in proportional. From the graph, all points are on the curve, which means that my record is very accurate. From the second graph, it shows that the ball is losing the same proportional of energy at each time. You can see that the points are not the line, because if the record is 1 cm higher or lower there will be a big percentage change, so that it is difficult to plot the graph very accurate. But from the graph, you can still find that each time the percentage lost is nearly the same. From the results I got, this tells me that my prediction is right, the energy is lost by proportion instead of losing the same amount of energy.
Evaluation
I found that the test is not very accurate, it is very difficult to record the result, the lower you bounce, the more errors you have, so that why I have to repeat the test for several times to get a better and a accurate result. My records are not too bad; there are 2 results that I don’t like so much, the 2 results that I have bolded. Those 2 results are quite out of the range between the others, but at least I am able to plot my graph. From the graph shows that the energy lost is by proportion instead of the same amount of energy. The result I got is what I predicted in the prediction. I think that my method is perfect nothing have to change, but I think I should practice more before the test, and make myself comfort, and don’t hurry when getting the result, wait for a while after I done the first record, then do the other one, next time when I do it again I will able to make it more accurate and get a better result.
