Newton’s Second Law of Motion
Acceleration with Weight
“Free and easy, down the road I go.”
Brian Gedrose
Jeff Newgard
Physics II Research Symposium
Background----Statement
of Problem----Review of Literature
Hypothesis----Method of Destruction----Results----Uncertainty
Discussion----Bibliography----Similar Websites
Has a friend ever made you help with gas money? Even though you’re both going to the same place? The most commonly used excuse is that an extra passenger is more weight, therefore the driver’s fuel economy decreases. This concept has been around forever; does more weight in the trunk of a car or in the back of a truck actually affect the trucks acceleration? According to Newton’s second law, the law of inertia, it should… There is only one way to find out.
We are planning to test this controversial theory using a 1996 Honda Accord, with a five speed transmission. To test our theory we are going to use 0-30 mph times as our main data source to tell us if more weight really does affect acceleration and, in the end fuel economy as an indirect result. We plan to add weight in fifty pound increments up to five hundred pounds.
The literature that we used to represent the facts and knowledge that we use in our symposium research project exemplify the laws and formulas of that in which we used to design, commit, and discuss our experiment. Sources such as the research centers at N.A.S.A are designed primarily to inform the audience of what the precise regulations of Newton’s Law, giving a collaborative collection of the definition and examples of inertia. The source included from Stanford’s physic department is an example physics project done on inertia that tests similar aspects of Newton’s Law, excluding the fact that ours has been done to show the law in the aspect of automobiles. Although the TUHS Physics page was cited, it is credible and useful because it contained the formulas that were needed for us to conduct our study. If the website itself can be deemed non-citable material, then the class would therefore be deemed useless. Since we are under the understanding that we are being taught the right material, it is fair to say that it use a reasonable citation.
Diagram
If the weight in a vehicle increases, then the acceleration of the vehicle will decrease because the vehicle needs to power more mass; therefore, slowing the vehicle; an indirect result being consuming more fuel, decreasing fuel economy.
We will use a standard digital stopwatch and time how long it takes the Honda Accord to go from zero to thirty mph, also recording the speed in which we were traveling when we reached thirty mph, the control being the weight of the car, me, and Jeff. We will be keeping the pressure on the pedal constant using a block of wood to restrict how far the gas pedal can go, pushing as far as the wood allows ever trial. We will be using one of the formulas derived from SUVAT problems, V=U+AT, solving for A (acceleration). Which, derived for A would be A=V-U/T. After knowing the final speed, thirty mph, (V) and the time it took to get the thirty mph (T), and the initial speed (U) obviously being zero, we can derive acceleration. After every attempt we will add a hundred pounds, up to five hundred pounds, recording the necessary data after every trial. We chose to conduct three separate trials for every measurement of weight, recording the time that we reach thirty miles an hour.
The time that we started with, testing the time with just the weight of the car, me and Jeff was 6.5 seconds… not bad for a Honda… Most of the data is recorded on the attached excel worksheet, but I will give the jist on what is going on. For the control, with only me and Jeff in the car, the acceleration calculated out to be 4.6 m/s2, (30mph-0mph)/6.5 seconds. As the trials continued, the acceleration acted as we predicted. We successfully did ten trials, not including the control with just Jeff and I in the car. To see the rest of the data see our excel spreadsheet and graphs, but in the end, after adding five hundred pounds, the time went from 6.5 seconds, to a drastically different 12.4 seconds, calculating out to be an acceleration of 2.4 m/s2. Almost half that of the control trial!
Table of the Results:
|
|
Trial 1 Time (seconds) |
Trial 2 Time(seconds) |
Trial 3 Time (seconds) |
Average Time |
Acceleration (m/s/s) |
|
|
Control |
6.5 |
6.3 |
6.7 |
|
6.50 |
4.62 |
|
100 lbs |
7.3 |
7.6 |
7.4 |
|
7.43 |
4.04 |
|
200 lbs |
8.5 |
8.8 |
8.6 |
|
8.63 |
3.47 |
|
300 lbs |
9.8 |
10.3 |
10.1 |
|
10.07 |
2.98 |
|
400 lbs |
10.9 |
11.1 |
11.3 |
|
11.10 |
2.70 |
|
500 lbs |
12 |
12.5 |
12.3 |
|
12.27 |
2.45 |
50 Pounds – .5 (Range of Times)/6.5 (Average of Times) = .08
100 Pounds - .3/7.43 = .04
200 Pounds - .3/8.63 = .03
300 Pounds - .5/10.07 = .05
400 Pounds - .4/11.10 = .04
500 Pounds - .5/12.27 = .04
Graph of the Results:
Based on our results and calculations, the next time a friend asks for some extra gas money for taking you to the same place as he/she was already going; don’t be hesitant to help them out, because your weight really does make a difference in the end. Our experiment is direct proof that having extra weight, whether it is another passenger, or just junk in the trunk, your vehicle will have to work harder while decreasing you fuel economy. The only lesson to basically learn from this is either kick your friend out, or get that junk out if you’re runnin’ on fumes.
Benson, Tom. "Newton’s Law of Motion." NASA Glenn Research Center. 15 June 2007. N.A.S.A. 8 Jan. 2008 <http://www.grc.nasa.gov/WWW/K-12/airplane/newton.html>.
"Data Packet (Formulas)." TuHS Physics. Tualatin High School. 2 Jan. 2008 <http://tuhsphysics.ttsd.k12.or.us/Tutorial/NewIBPS/Data_Packet_03.htm>.
"Newton's Law." Natural Science 101. University of Arizona. 12 Jan. 2008 <http://www.ic.arizona.edu/~nats101/newton.html>.
"Virtual Spaces: VR Projection System Technologies and Applications." Stanford University. 1997. German National Research Center for Information Technology. 12 Jan. 2008 <http://www.stanford.edu/dept/SUSE/projects/ireport/articles/3D/Eurographics'97%20Virtual%20Spaces%20Tutorial%20Notes.htm>.
Newton's Second Law - The basics of Newton's second law of motion
Applying Newton's Second Law - A series of example experiments
Definitions of Newton's Second Law - Mathematic definitions of Newton's second law and examples
Thrust to Weight Ratio - Another example, considering an airplane in flight
Newton's Second Law Experiment (Interactive) - A cool interactive experiment to punch in numbers and see what happens!