To proceed with my experiment I shall elevate the rear end of my wooden plank to 10 cm high, using the clamp stand, while the front end sits on the floor. I shall release the car 30 cm away from the front end of the ramp and after that has been done three times I shall increase this clearance distance by ten until the clearance distance reaches 110 cm. I shall ensure that the vehicle has a clear path to travel once it has left the slope and that the path ahead causes minimal friction to obstruct the vehicle and my experiment. I shall achieve this by conducting my experiment on lino flooring. As I release the toy vehicle from the different points on the ramp, I shall concurrently activate the stopwatch until the vehicle leaves the ramp at which point I shall deactivate the stopwatch and record the time. Once I have recorded the clearance time, I shall wait until the car stops travelling along the floor. When it has come to a halt, I shall measure the distance between the front end of the ramp to wherever the car has stopped and record this also. With each height I shall do the same and will present the average stopping distances and ramp clearance times on a table and graph. Following is my preliminary results table:
From my preliminary results I have decided to utilise the following apparatus:
1X wooden plank of 1.1 m to 1.5 m in length. Required to act as a downward slope.
1X Toy vehicle that can move freely without restraint. The chosen matter weighs approximately 23.8 g.
1X Meter ruler required to measure distance travelled by car.
1X Stopwatch required to time the car’s movement.
1X Clamp stand required to change gradient of wooden plank.
To ensure that I conduct a fair test I shall keep the car I use constant throughout my entire study, thus the vehicle’s mass shall remain the same (23.8 grams). I shall also use the same ramp and same floor during my experiment. The only variables will be the gradient of the ramp and the point at which the vehicle is released.
In order for me to complete this study I have divided my experiments into three separate experiments:
1) In the first experiment I shall change the height of the slope and keep the ramp clearance distance constant. I shall not change the mass of the vehicle in any of my first two experiments.
2) In my second intended experiment I shall change the length of the ramp but the gradient of the ramp shall remain constant.
3) In my third and final experiment I shall keep the length of the slope constant as well as the gradient but shall alter the mass of the vehicle by adding plaster sine.
My apparatus will be set up as below:
I will time the clearance distance from point A to point B. I will measure the stopping distance from point B to point C. I shall record these results on a table and then plot them on a graph.
An Investigation Into The Effect Of Speed Of A Vehicle On Its Stopping Distance.
Method.
For my three experiments I necessitate:
1X Stopwatch to measure the ramp clearance time.
1X Plank of wood to act as ramp.
2X Meter ruler to measure distance travelled by the car from the front end of the ramp.
1X Calculator to calculate averages, speeds, etc.
1X toy car to act as vehicle.
Plaster sine.
1X Weighing scale to measure mass of vehicle.
I shall enter the data I collect from each experiment into a table and then a graph as follows:
Experiment 1: The effect of gradient of ramp on stopping distance.
The car I shall use in this experiment will have a mass of 23.8 grams. I shall keep the clearance distance constant throughout this experiment. I shall select a gradient or rear height for my ramp and record it. I shall then release the car three separate times and write the clearance times and stopping distances into the table and also any other relevant information for each release. I will then do the same on another six different gradients and then plot a graph of my results showing the speed at the bottom in m/s against average stopping distance. All my graphs will show the same.
To calculate the speed at which the vehicle is travelling I shall use the following formula:
Distance Travelled = Clearance Distance
Speed X Time Speed X Clearance Time
To calculate the speed at the bottom I shall multiply the clearance speed by two.
Experiment 2: The effect of clearance distance on stopping distance.
I shall use the exact same car in this experiment as the car used in the first experiment (23.8 grams). I will select a suitable gradient and keep this constant also. The only variable in this experiment will be the clearance distance. Other than these few details, the experiment will be identical to the first.
Experiment 3: The effect of vehicle mass on stopping distance.
In my last experiment to study the effect of mass of vehicle, I will only alter the mass of the vehicle; the gradient and clearance distance will be kept constant. The method of calculating speed, etc. will remain the same and the recorded data will be collected in the same manner as mentioned in experiment 1.
Insert table 1,2,3 and graph 1,2,3 then continue to analysis etc.
7 top spaces 9 bottom spaces
An Investigation Into The Effect Of Speed Of A Vehicle On Its Stopping Distance.
Analysis.
After plotting my graphs, I decided to use the lines of best fit to estimate the results I would get if I were to use different input data. I will use these different input data to analyse my results. For this I will be required to calculate the amount of energy required by the vehicle in order to reach the speed it was travelling at. I will do this using the following formula:
½MV2 = Energy in joules.
In the above formula, ‘M’ is the mass of the vehicle in kg and ‘V’ is the speed of the vehicle in m/s.
Experiment 1: The effect of gradient of ramp on stopping distance.
Experiment 2: The effect of clearance distance on stopping distance.
For the above two tables, I expected the stopping distance to increase by four times because energy required is four times as much in order to double the speed.
These first two tables clearly demonstrate that the results are not as they are expected to be.
Experiment 3: The effect of vehicle mass on stopping distance.
On the third experiment, illustrated above, my only variable was the mass of the car. It can be seen on the above table (table three), that the results were extremely close to what they were expected to be.
I have already explained that the energy used is four times as much when the speed is doubled, so theoretically, the stopping distance should also increase by four times as much because four times the original energy is being used. Having known this fact, my results still did not prove my theory because they were quite inaccurate.
In table 1 shown above, when the speed is 2 m/s, the stopping distance is 1.4 m; and when the speed is double that, at 4 m/s, the stopping distance is 2.2 m whereas it should be 5.6 m. it is 3.4 m out of what it should be while the energy input is all being used.
An Investigation Into The Effect Of Speed Of A Vehicle On Its Stopping Distance.
Conclusion.
According to my results, my theory and prediction was incorrect.
I had predicted that when the speed is doubled, the stopping distance is four times as far because four times the energy is being used. This is incorrect because one of the factors that I overlooked was that the energy would be used in other forms than just kinetic. Sound and heat energy would have also been created and energy would have been used here also. However if the energy input was transferred into only kinetic output energy, then my theory would have been correct.
Also, I claimed that if you double the mass, the stopping distance is nearly doubled because twice the energy is being put in. This was also incorrect due to the fact that energy would be released in different forms, not just kinetic.
Some of the other factors that caused inconsistencies in my investigation were:
1) Air resistance – the greater the air resistance, the more movement energy is required to counter that. The air resistance also meant that the vehicle was accelerating for a much shorter time.
2) Friction – this is the force that opposes a surface from movement over another surface. It builds up and heat energy is caused along with counter resistance. The grip of the car wheels and the car axle can cause this. It can be prevented using a lubricant such as oil.
3) Direction – a vehicle is not always in the exact same direction even if it appears so. The car could have been moving off of the shortest route possible by not travelling in a straight line.
4) Aerodynamics – the shape of an object determines whether the object is streamlined or not. Streamlined objects offer less resistance against movement, which means the vehicle accelerates for a longer period of time and so is travelling faster and will have a greater stopping distance.
An Investigation Into The Effect Of Speed Of A Vehicle On Its Stopping Distance.
Evaluation.
There were a few main factors contributing to the errors that occurred in my experiment:
1) My timing of the clearance distance
2) My measuring of clearance distance, stopping distance, gradient and other distances.
To correct these two factors, I could have asked for more assistance in taking readings, etc. and for more accurate equipment and this would have helped greatly.
I could have also created some method of checking the direction of the car such as attaching a piece of string to the rear of the vehicle and this would have helped me visualise the cars’ direction.
I could have also taken more precise readings for my graphs and thus I would have had a more precise graph.
If I were to conduct this experiment again or for longer, I could have corrected the inconsistencies by experimenting with the surface area of the cars, the floor I tested everything on, etc. I could have also tried it with real cars but this would have been more time consuming and there aren’t hills that could be used for such an experiment everywhere.