PREDICTION
I predict that the higher the ramp is the faster the speed of the trolley will be and the average velocity and time will not be directly proportional.
Due to gravitational potential energy (GPE) which is the amount of energy that an object has because of its position, the higher the object is the more GPE it has. Therefore at the top of the ramp the trolley will have more GPE, than when it has come off the ramp.
GPE = mass x g x height.
However when the object begins to fall its GPE is converted gradually into kinetic energy (KE).
KE = 1/2 x mass x (velocity)2
Therefore at the top of the ramp the GPE is at its maximum and at the bottom of the ramp the KE is at its maximum, this is because the energy is being converted as it cannot be destroyed. I can therefore presume that as the height of the ramp is increased the velocity of the trolley will also increase.
METHOD
To perform this experiment, we will work in pairs as this will make the experiment less complex. Setting up the apparatus will be one of the hardest parts of the experiment. The first thing we will do, is set our ramp at an incline carefully adjusted so that no force will change the speed of our trolley. This will be set-up by clamping the ramp securely and accurately at each height. I will then place some sponge at the end of the ramp as this will prevent the trolley from going off the end of the ramp consequently affecting its velocity.
We will then take a power adapter to power our ticker timer dispenser and will connect those using plugs and when the time is right, power it to the correct voltage in order for it to record dots onto the ticker timer paper. We will then cut some self-marking ticker timer paper and thread it into the ticker timer machine assuring us that there is carbon paper in the ticker timer device and we will then selotape the other end of the tickertape to the back of the trolley. Then I will complete setting up my apparatus by hooking the back wheels of the trolley onto the top of the ramp as we have decided that we will measure everything in regard to the trolley in accordance to the rear of it. We will then, be ready.
Diagram to show how I will set up the apparatus:
Once I have set up my apparatus like so, I will switch the ticker timer on and release the trolley so that it can accelerate down the ramp. I will measure its velocity from the very point it leaves the ramp for 1m. I chose 1m as it is a suitable distance, if I was to have a number any smaller the trolley may not have yet reached its average speed.
I will carry out the investigation, by doing each height 3 times to ensure accuracy in the results.
SAFTEY
There are no real safety issues to worry about, however to be certain that there are no injuries, we will make sure everyone's ramps are well spaced apart, to prevent any trolleys colliding into anyone. And that our ramp is very stable to prevent it collapsing and hurting someone.
RESAULTS
1ST
Height (m) Distance (m) Velocity (m/s)
0.1 0.26 0.26/0.2=1.3
0.2 0.277 0.277/0.2=1.385
0.3 0.281 0.281/0.2=1.405
0.4 0.336 0.336/0.2=1.68
2ND
0.1 0.29 0.29/0.2=1.45
0.2 0.28 0.28/0.2=1.4
0.3 0.291 0.291/0.2=1.455
0.4 0.312 0.312/0.2=1.56
3RD
0.1 0.22 0.22/0.2=1.1
0.2 0.25 0.25/0.2=1.25
0.3 0.273 0.273/0.2=1.365
0.4 0.336 0.336/0.2=1.685
Analyzing Evidence
Looking at my graph in obtaining evidence I am able to make a conclusion, which proves my prediction to be correct. That the greater the height, the faster the velocity. However as the height doubles the velocity does not.
For example when the height was 0.2m the average speed was 1.345m/s, yet when the ramp was set at an incline of 0.4m the average velocity was 1.541m/s.
My results display that the higher the ramp the faster the velocity of the trolley will be. This is because an object, which is a certain distance above the ground, has gravitational potential energy (GPE), and when the trolley rolls down the ramp this energy is converted gradually into Kinetic Energy (KE). By the time the trolley reaches the end of the ramp all the GPE will have converted to KE.
Evaluation
In conclusion to the investigation, I believe that the experiment went very well, I did not overcome any major difficulties, and feel that I achieved the best of my abilities. However given more time and better apparatus to measure the velocity of the trolley I think it could have been more accurate. Possibly a centisecond timer or millisecond timer which have the sensitivities to be able to measure the velocity of the trolley up to 1/1000s would have guaranteed better accuracy. Nevertheless I am pleased with the experiment. Taking 3 sets of results on each height proved the ticker timer to be dependable as both the readings were practically the same each time. By taking 3 sets of results also ensured myself that I should not get any weird results, which I didn't, I know this as the line of best fit went through my plotted results on my graph. Given more time I would have repeated the whole experiment and maybe taken 5 or more readings of each height to guarantee that my results were reliable. Furthermore, I am still sure that my results are of a high degree of accuracy and are dependable enough to draw a reliable conclusion.
