The effect of speed on braking distance Essay Example

The effect of speed on braking distance Essay Speed is the travelled distance for every moment/unit of a set time. Speed, distance and time are all related with each other, shown in the following equation, which can be rearranged to find the formula of each measurement:Speed (m/s) = Distance (m) à ¯Ã‚ ¿Ã‚ ½ Time(s)The braking distance of an object is the distance it takes to slow the object down, until it is has stopped (stationary). The object will only become stationary when the driving force is being counter-forced, for example friction and air resistance.The kinetic energy of an object is the energy it gains due to its motion. The equation for kinetic energy is:What factors can affect the braking distance of an object?Well there are 3 main factors that affect the braking distance of an object:The height from which the object is releasedThis can affect the braking distance as the higher the object is when it is released, the greater its original GPE. As the object continues downwards, its GPE decreases, and its kinetic energ y increases by the same amount of gravitation potential energy lost. Yet still, the increase in kinetic energy is never exactly equal to the amount of GPE lost, as friction and air resistance (the forces acting on the object) transfer some of this energy into heat and sound.The surface the object is travelling onThis can affect the braking as different surfaces have a varying amount of resistance force (friction.) E.g., ice is more slippery than a rough surface because it is very smooth, and therefore exerts less friction on the object travelling on it. The friction force gradually converts the kinetic energy of the moving object into different forms of energy such as sound and heat, until the objects kinetic energy is reduced to zero hence why it always stops eventually. The longer it takes for the object to have its kinetic energy reduced to zero, the longer the braking distance.The mass of the objectThis can affect an objects breaking distance because if the mass of an object is doubled, its kinetic energy will be increased, and as a result more work will need to be done by the resisting surface to convert the objects kinetic energy into other forms of energy in order to stop it.In this experiment, I will be investigating the effect of a balls speed on its breaking distance. I will be dropping the ball from certain distances along a ramp, which is positioned at a certain height along the clamp-stand. As well as that I will also be using a carpet as I will need to slow the ball down as it travels down the ramp.MethodThere are numerous methods to measure the speed of the ball as it travels from the ramp and onto the carpet. These are the two methods that I have used during the Preliminary in order to test out which is better, and why. The following table lists both its advantages and disadvantages, of the methods, and also have brief description about each one.The table below lists the advantages and disadvantages of possible methods, and describes how they are to be carried out.NameDescriptionAdvantagesDisadvantagesStopwatchMeasure the time taken for the ball to leave the ramp when travelling on the carpet. Use the dropping distance (measured on the ramp) and the time taken to calculate the speed using the speed/time/distance formula.This is a very quick method, which is easy to execute.The stopwatch isnt very accurate; as it is very hard to know when exactly where the ball has moved along the ramp, and thus can cause confusion as one person may begin the timing of the stopwatch at a different point than when another person would tell them to, hence having an effect on the results.Light-gateConnect a light-gate device to a computer, and place it where ever you want to position it in order to calculate the balls speed, works by using a laser beam as a light sensor detecting how fast the ball is going.This method is very precise and accurate as the results itself can be displayed on the computer, as a graph or a table. So precise even t hat it can go up to six decimal places. As it being on a computer, it is easier to notice any trends or patterns in the graph/table. Also easier to transfer data across (USB)As the Light-gate is very accurate it can be a pain when setting up as the light-gate would need to be in the right place as it would cause a great effect on the results resulting in the unreliability of the results.As a result of this analysis of the methods, I decided to use the more proven and more accurate and reliable method, the Light-Gate. This is because it will be easier to record, less hassle, more time to work on the experiment as it will be very quick and easy to do, and will be easier create graphs and tables, and make conclusions from the data as it will be easier to spot any trends.The Equipment Needed.* Light-gate device* Computer/Laptop (preferably a Laptop)* Ramp* Clamp x2* Clamp Stand x2* Metre Stick(s) (depends on how far the stopping distance is)* Carpet (depends on results of Preliminary)* Ball (also depends on results of Preliminary)Here is a diagram of how it should look:Step-by-step Method1. Connect the clamp to the clamp-stand.2. Mark out regular-distance intervals along the ramp, using the metre-stick as a guide.3. Connect the ramp to the clamp, at a certain height along the stand.4. Lay the chosen carpet on the table, smoothing out any bumps.5. Position the ramp on the carpet, so that the two overlap each other at the edges.6. Connect the light-gate to the laptop.7. Place the connected light-gate in front of where the ramp overlaps the carpet.8. Place the metre-sticks horizontally along the carpet, placing the 0cm mark at the point where the ramp light gate is.9. Position the chosen ball(s) at a certain distance along the ramp (at the appropriate distance-interval)10. Release the ball, letting it travel down the ramp and onto the carpet.11. Ensure the light-gate is recording the speed of the ball.12. Measure the stopping distance of the ball on the carpet using the metre-stick. (Use a second metre-stick if the stopping distance exceeded 100cm.) (place the metre stick along the carpet aligned to the light gate)13. Repeat Steps 11 to 13 five times, re-setting the light-gate before each further trial.14. Repeat steps 10 to 14 for each distance-interval along the ramp. (All distance-intervals need to have a trial and five further repeats before continuing on to Step 16.Safety Procedures* The Apparatus shouldnt be ANY WHERE near the Computer or Laptop, as the rolling ball might causes damage to it* Clear out the space that you are using from anything, from bags to books.* No water anywhere, in fear of damage to equipment (laptops, Light gate etc.)PreliminaryBefore even doing the real experiment, we needed to make sure what equipment we were going to use in the real experiment, and so we decided to test out the equipment and to familiarize myself with the equipment to then use in the investigation. E.g. Using the Laptop correctly, prevent mistak es to happen in the real investigation. As well as that I need to ensure that the equipment that Ill be using in the investigation will be the most accurate and most reliable ones.Instead of just the equipment, I will be also testing out the:* Type of ball (golf, marble, small silver, etc.)* Type of Carpet* Ramp heightsThis I will be testing on as, I will need to know which will produce a good batch of reliable results, from which a Speed against stopping distance graph could be drawn from.The reason why Ill be testing the different ramp heights is that in order to get the best results, I will need to know what height the ramp should be as, if too high then the ball will travel too quickly/far, and vice versa. This is because the greater the height of the ramp, the greater the GPE and therefore its Kinetic Energy.The reason why Ill be testing different types of carpet, as Ill need to find out which carpet will be the best one to use, as Ill need a carpet that allows the ball to trav el a good distance on the carpet before stopping. But a bad carpet will allow the ball to go too fast/slow.Preliminary ResultsChoosing which ball to use:Small metal ball Rolled of the CarpetMedium metal ball Stopped in the carpet went straightGolf ball Curved a little on the carpetSquash ball Curved a lotFrom these results, we decided to use the medium metal ball as it was the only ball that went straight.Choosing which method to use:Firstly, we carried out a test using the stopwatch method as a way to measure the speed of the ball; we also changed the height of the ramp to increase/decrease the speed of the ball. After numerous trials, we relised that moving the ramp up and down was harder, more time-consuming and was less accurate. Using the stopwatch to workout the speed was also a very long process as we had to work out the time takenBased on the results from the Preliminary, we chose to use:* The golf ball and the marble (to compare with each other in graphs)* The light gate m ethod* Height of 15cm of the ramp* The orange carpet* Drop the ball from different points on the ramp from 10cm-90cm (this was good range as we needed a good range of results in the graph)Results Table60mReadingSpeedDistancem/smm10.8250844520.8333343530.8250845040.8389345450.8278145050mReadingSpeedDistancem/smm10.7163334320.7022527730.7102332040.7122532050.7225434840mReadingSpeedDistancem/smm10.7246432520.7418428030.7462733140.7374629350.7530131990mReadingSpeedDistancem/smm11.1210873021.106271931.1261376041.1160774951.1261372380mReadingSpeedDistancem/smm11.0548564621.0416764431.0416767641.0460365851.0416765970mReadingSpeedDistancem/smm10.9469756420.9505757030.943456940.9469758150.95057581Height Dropped (cm)Average Speed (m/s)Average Distance (mm)900.2341800.46134700.61219600.74310500.71322400.83447300.95573201.05657101.1273630mReadingSpeedDistancem/smm10.5952421220.6234421430.606820640.5952422450.6265724020mReadingSpeedDistancem/smm10.4553713720.456213330.4496413740.4664213150.46041 13410mReadingSpeedDistancem/smm10.248023920.225434030.238324040.229574350.2175843MARBLE RESULTSDiameter =1.6cmWeight = 4.2g (1d.p)Height Dropped (cm)Average Speed (m/s)Average Distance (mm)901.221080801.11926701.04791600.94659500.83538400.71416300.61312200.48200100.3093GOLF BALL RESULTSDiameter = 4.2cmWeight = 45.7g (1d.p)90 cmReadingSpeedDistancem/smm11.20413103021.22893109031.22893111041.24055112051.18243105030 cmReadingSpeedDistancem/smm10.5933529720.6093331530.6156231440.6031731550.6082031920 cmReadingSpeedDistancem/smm10.4821820520.4879220630.4605318740.4717819850.4800720410 cmReadingSpeedDistancem/smm10.307529420.297489330.287079240.296689450.294029440 cmReadingSpeedDistancem/smm10.7133241620.7172141230.71141040.6951841150.7219542950 cmReadingSpeedDistancem/smm10.828653420.8317553030.8567256340.823453050.8317553160 cmReadingSpeedDistancem/smm10.924362720.9483462830.9442467640.9415467850.9483468470 cmReadingSpeedDistancem/smm11.0253978521.0400280531.0466578741.02776551.05676811 80 cmReadingSpeedDistancem/smm11.1295295321.1141892631.0901288641.1160793451.1218932AnalysisIn this experiment, I am investigating the effect of a balls speed on its breaking distance. But in we need to be able to understand what is going on as the ball is released from the ramp and when it stops. I will try to explain this scientifically.EvaluationProblems I encountered while carrying out the experiment:How I would improve the experiment if I did it again:As the light gate needed to be at the correct place in order to get a good set of results, it wasnt always at the same place thus affecting the results.Leave it at the same place, or leave a mark so we know where we put it.When a heavy ball would roll on the plastic ramp (Golf ball), the ramp would bend, thus decreasing the speed of the ball greatlyUse a rigid material e.g. Iron, as it would not bend.The ball not travelling straight meaning the distance is decreased. (e.g. it would go diagonal)Although I managed to obtain a good s et of results from carrying out the experiment, there were several difficulties in trying to collect valid and reliable data. The following table describes the problems I encountered while carrying out the experiment, and suggestions on how I would improve the experiment if I had to repeat it.Confidence on the ConclusionOn the whole, I am quite confident with my conclusion. I attained a set of results which strongly suggested that speed of the ball had the effect on the balls breaking distance. Although, as most of the graphs show, many of the range bars are a bit large, meaning that the results are not very reliable as there is a large scatter of data, perhaps this was because of the ramp bent as the ball rolled on or that the light gate wasnt positioned correctly at that time, justifying the reason why its results was so scattered.Throughout the experiment, I had obtained many outliers in my results, as shown by the 2 Tables. These may have occurred because of any of the following reasons:* On some repeats, the position of the light gate wasnt in the same place as other repeats or therefore makingDespite these outliers, the majority of the averages were close to or on the curve of best fit, so after eliminating outliers, the results were reliable on the whole.