When finding my speed I will use the equation 1÷average time this will give me the calculated speed.
Diagrams
Equipment
Ball
Ramp Bench
When ball rolls down ramp
When ball reaches the meter mark
Prediction
I think that as the ramps height increases the ball will travel faster, therefore losing its potential energy and gaining kinetic energy. Some energy will be lost through sound and friction.
My prediction is shown as letter A on my graph below.
Line A shows that as the height of the ramp increases the velocity becomes slower.
Line B shows that as the height increases the velocity becomes faster.
Line C shows that as the height increases the velocity stays the same.
Line D shows that as the height stays the same the velocity increases.
Hypothesis
I predicted this because when the ball it at the top of the ramp it will have maximum potential energy, but as the ball travels down the ramp the potential energy decreases and is transferred into kinetic energy. This will happen because of the low conservation energy meaning energy cannot be lost it can only be transferred. Some energy will be lost through sound and friction caused by the ball going down the ramp. At the bottom of the ramp the kinetic energy will be at its maximum as all the potential energy has transferred into kinetic making the ball roll faster. The ball will travel faster at the highest height because the higher the ramp the more potential energy, therefore transferring into more kinetic energy.
Formula for potential energy
PE = m x g x h
Potential energy = Mass of ball (kg) x Gravity (10m/s/s) x Height of ramp
Formula for kinetic energy
KE = ½ x m x v2
Kinetic energy = ½ x Mass of ball x Velocity2
So because of a low of conservation of energy with means energy can not be destroyed only changed. In this case it is potential to kinetic.
So
PE lost = KE gained
m x g x h = ½ x m x v2
But because there is m on both sides of the equation they cancel each other out.
g x h = ½ v2
2 x g x h = v2
g represents the gravitational pull as we are on earth this is 10 m/s/s
2 x 10 x h = v2
20 x h = v2
So I just want to find velocity not the velocity2
√20 x h = v
Remember the height will change according to the experiment.
Method
When I did the actual experiment I made several alterations to what I wrote in my plan. First instead of doing the experiment on a bench we did it on the floor because we found the bench to be too small a work area. Also we had to hold the ramp in place because the clamp was not sufficient as it only reached 0.60 meters and we needed 1 meter.
Table to show the results of the ball rolling experiment
Analysis
My graph shows that my prediction is correct; which was as I raised the height of the ramp the ball would travel faster. Both line of best fit on my graph have positive correlation which means the higher the ramp the faster the ball will travel. (Line b in my hypothesis). When looking at my graph I noticed an irregular result at 1.00 meter. This could have been cause by human error when doing the experiment or because of the ball bouncing on after 0.60 meters the bounces becoming higher as the ramp was raised. Both line of best fit are quite similar both slightly curving but calculated speed curving back whilst theoretical curving in. Therefore showing that although the lines of best fit could be a little more similar that as the theoretical speed raises so does the calculated but not both speeds raising the same amount/rate. My graph relates to my hypothesis because at 0.20 meters the potential energy will be less than any other higher height, therefore transferring into less kinetic energy so travelling at a lower speed.
Both my calculated speed and my theoretical speed are similar and at 0.80 meters they are the same at 4 m/s.
Evaluation
The experiment I did was a suitable way for collecting the results I needed to assess my hypothesis and my prediction because it showed the energy transfer well. I think that the accuracy of my experiment was O.K. considering the limited amount of resources we had. The fact that I did the experiment three times instead of two increased the accuracy. One thing which was not accurate was the fact that after 0.40 meters I had to hold the ramp which may have caused the ramp to move and therefore affecting my results. Also I had to time the ball when travelling one meter with a stopwatch which would have been affected by my judgement of when the ball reach the meter mark making my results inaccurate. Another inaccuracy was as the ramp reached 0.60 meters the ball began to bounce which could affect my results. An odd result was located at the height of 1.00 meter, as it was quite far from my line of best fit. This could be because of the human error when holding the ramp or when timing how fast the ball travelled. To make my test more reliable I could have used the same person when holding the ramp and the same person timing. Also making sure the ramp was at the same angle. By using a large clamp reaching one meter I could of made it much more reliable because then the ramp would not move. Also by using speed gates at the start of the meter mark to start the time and at the end of the meter mark to stop the time, making it more accurate and eliminating human error. To stop the ball bouncing after 0.60 meters I could make the foot of the ramp curved so the ball will travel more smoothly making my result accurate.
I could provide additional evidence to extend my enquiry by testing a large variety of heights and testing each height more times to make my results more accurate. Also I could extend the meter which the ball travelled to a longer distance giving me a variety. I could investigate other factors of this experiment by changing the mass of the ball or the texture of the ball but using the same equipment as I have in testing the height. I could also change the texture of the ramp or/and of the worktop to tell me how friction affects the ball when travelling.
Conclusion
My conclusion is that if the height of a ramp is increased the speed of a ball travelling down the ramp would be increased too making the ball travel faster across the 1.00 meter mark, due to the large amount of potential energy transferring into kinetic energy.
So the higher the ramp the more potential energy which will turn into more kinetic energy so the ball will travel faster.
