Factors that could affect this experiment are the following:
Angle of the Ramp
The experiment could be affected by the angle of the ramp for example a 10° angle could have a higher amount of potential energy than a 3° angle.
Surface type of ramp
The surface of the ramp may affect the outcome of the results because any type of grip on the surface could slow it down and also such things as lubricants on the ramp could make the ramp slippery in effect speeding up the ramp.
Mass of the trolley
The mass of the trolley affects the results because the weight could either slow it down or even speed the trolley up, as there will be a greater amount of potential energy pulling on the trolley.
Surface of wheels
The surface of the wheels could affect the trolley because just like the ‘surface type of the ramp’ the wheels could slow it down, as this is the effect of any type of traction provided by the wheels.
Practice Tests
I carried out some practice y tests to see any problems, which could occur and anything, which could be improved. I first tried timing the trolley with a ticker timer. I place the ramp at an angle of 5° to test the ticker timer. I attached the tape to the back of the trolley and turned on the ticker timer whilst letting go of the trolley the result was 96 dots. Which meant in seconds is 96/50 = 1.92 seconds. Although we felt this was accurate we felt it would be very time consuming to count 40-50 lengths of tape. So we decided to use a lap top although this may be slightly inaccurate because of the result being reliant on the timers accuracy holding the lasers, we felt this to be most efficient. By setting at 5° we got a result of 1.39s. The results of the experiment with the laptop are shown below:
After the 20° angle we found it was becoming difficult to time the trolley and also to support the ramp. So we decided to change the range from 5°- 45° to a more suitable range of 3° - 30° and also to carry out the experiment 5 times instead of the 3 allowing us to get a better average.
Apparatus:
Trolley
Ramp
Metre stick
Angle measurer
Laptop
A materials to hold up the ramp e.g. books
Diagram:
Method:
Collect the apparatus
Set-up as shown in the diagram
Set the angle of the ramp at 3°
Mark in a start line
Mark 1 meter from the starting line
Place he trolley at the top of the ramp and let go
Start the timer when the trolley passes the start line
Stop the timer when the trolley passes the finish line.
Put the result into the result table and repeat experiment 5 times
Add 3° to the angle and repeat the experiment
Fair test
The experiment will be a fair test as there will only be one variable factor: the angle. All the other factors will stay the same such as the material used and the trolley used this means that there will not be any bias issues in this experiment. Other factors that might affect the experiment may be that of the angle being ±0.1°
Results
Final tests
From the results I could then find the speed at which the trolley traveled down the ramp this is worked out by the formula
Speed = Distance
Time
The speeds are then shown in the table:
Conclusion
From looking at the results it is clear that both my aim and predictions were achieved and that the prediction was correct. I also found that the speed was increased and that the potential energy increased with the angle.
Evaluation
I felt that the experiment was done to the best of my ability and went well overall. I did all that I could to ensure that the investigation was fair except for the fact that we used a manual laptop instead of a ticker timer. Although another negative side being that the books that we used to hold up the ramp could have one of two effects. One that they could alter the angle slightly which affects the results. Two it may allow the wood to slip or even tilt to one side which may effect the results too. Using the books and the laptop were both not scientific which meant that the results could be possibly bias. To improve the investigation I would redo the experiment in the same fashion but use the ticker timer and a better material to hold the ramp in place. Although I still feel that my results were accurate enough to draw a firm conclusion as I had repeated the experiment 5 times and found an average which gave the desired result.
