# Road Safety Lab Report

The aerodynamics in the force pushing against an object is called drag a force that acts on a solid object while it moves through the direction of the airflow. This allows the object to slow down while in state of motion due to the drag. Also the friction caused by the surface material and wheels of the vehicle engage the speed to decrease only passing a short amount of distance to be reached. Newton’s First Law states, every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it (Newton’s Three Laws of Motion).Thus proving the fact the increase of surface area is an external factor, which will alter the objects state of motion, decreasing velocity, or decrease of surface will alter the increase in velocity. Hypothesis: predict that as the amount of the surface area increases the total of the stopping distance decreases. I am able to predict this as a result to my knowledge of air resistance. The distance that is then traveled depends on the opposition force acting against the surface area and the friction created between the velocity and surface of the path.

Apparatus: ChairRamp Wooden Car Masking Tape Measuring Tape Scissors Corrugated plastic Meter Stick Diagram/Photos: Method: 1 . Collect the apparatus listed above 2. Set up the chair and the place the ramp on top of it 3.

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From the bottom of the ramp use the measuring tape to measure at least mm 4. Cut two pieces of the congruent shape from corrugated plastic, both 50 by 10 5. Tape the pieces vertically on both ends of the wooden car 6. Set up ramp according to the height of the chair 7. Set car on the ramp and position so that the end of the car is align with the top of the ramp 8. Align the direction of the car so that it may go straight 9.

For example in trial 1 when we added no additional surface area to the car, the average stopping distance was 4. Mm, but then when we added comma of surface area the average stopping distance went down to 4. Mm. In short, this happened due to the increase of surface area manipulated for each diminishing distance that it reaches by the air resistance or drag that affected the additional rear which then it decelerates also caused by the friction of the opposition forces against the relative motion of the car.Thus proving my hypothesis to be correct that as the amount of the surface area increases the total of the stopping distance decreases. The reliability of the data because of the fact that there is a trend, which follows the hypothesis I personally feel that for the most part, the data is reliable, as the experiment was conducted in a purposefully reliable manner. Evaluation: The Reliability: During this experiment we used a lot of different equipment in order come up with our results.I would like to evaluate the equipment the car and the ruler.

The car that we used was causing a lot of problems during the beginning stages of our experiment because whenever we let it go on the ramp, it would always tilt in different directions, which therefore caused our car to misinterpret the total stopping distance. It didn’t take us long to realize that we were holding it wrong that was causing the problem, by holding it by the metal point so that it may accurately align with the top of the ramp.However, when we held the car by the sides of it and straightened by positioning the path it would take. So we decided to set the car at a firm direction before it went down the ramp so that it was straight. For this particular experiment we decided to have three trials for each variable primarily because most of the time, the results that we came up with varied. We also had to keep in mind that we were going to have outliers while experimenting, which more or less were going to have an effect on our data.

Having a number of trials and averaging the data for each measurements were pretty good ideas in my opinion because by doing that, we would be able to guarantee accurate results. The Validity: The equipment that were used were highly valid especially the material used, because we needed a stable a material that would be affect by the air resistance and still maintain shape also we carried out the experiment all in one day, therefore there could not have been a switch up between the correct equipment and the wrong ones.Also, our teacher helped us acquire material (corrugated plastic) for the experiment so that it would make the lab more reliable and valid based on the stability of the material, which further increases the level of validity, u to the fact that if we (the students) were to gather the required equipment, we could have gotten mixed up between which tools we actually needed and which ones we didn’t.

But since a more experienced person is gathering the material, the validity level of the lab steps up greatly.We were able to measure the distance according to the measuring tape, which was placed right at the end of the ramp and record the data by using the meter stick to align with the end of the vehicle to the distance marker on the measuring tape therefore having valid record of our data. We were able to control all variables but some anomalies of the surface of the road would allow some discrepancies with the data.As the surface of which we were conducting our experiment was made out of marble tiles the friction between the car and the spaces between the tiles would altered the speed of the vehicles at which it was traveling and would have modify the stopping distance. Therefore affecting the performance and validity of our data results.