*Use this link to guide your investigation report. Investigation of Time vs angle for wheeling car down inclined plane name: Raihan Adzkia date: - February - 2012 Aim: How does changing the angle of inclined plane affect the time? Variables: Independent
The Angle of inclined plane
Dependent
Time travelled of wheeling the car to achieve the ground
Control a)constant
The gravity
Control b) related
the distance of the starting point to wheel the car
Hypothesis:
. H symbolizes as height, and g is for gravity. That is the formula of finding time. According to that formula, it is shown that T and H are in a relationship. If Time is related to height(angle), then changing the height (angle) of the inclined plane will result in changes in time. Since the height of each experiment are different, therefore angles in inclined plane will effect the time of the object to achieve to the ground. To sum up, if the height of the angle gets higher, the less time needed to get the car to achieve the ground. The gravity constant is needed to find the time travelled of the object, and this might happened because the changes of the surfaces make differences of friction force.
Materials: ● A Stopwatch ● A protractor ● Thick books ● A table ● A car toy Procedure/Method: A. Prepare all the materials that is written above. B. Make the inclined plane by using A board: 1. Take a board that has flat surface on it. (make sure there are no any bumps on it)
apple 2/28/12 9:14 AM Comment: You must give a source for this equation. If you derived it yourself/with me you need to show the derivation.
apple 2/28/12 9:15 AM Comment: Good. But, You could just use a more general argument. You could just say that gravity causes the motion of the car. Gravity acts down. The board stops the downward motion. So, if the board is put more vertical – more downward – there will be more acceleration due to gravity and less time for it to travel the same distance.
2. Put the books on the table 3. Make an angle by putting the board onto the books. 4. Adjust the angle by moving the books and check the board so that it wont fall off. 5. Increase the height of the inclined plane by adding or decreasing books, which also changes the angle of the inclined plane itself. 6. Measure the angle by using a protractor, look at the numbers carefully so that we could get a reliable result and don’t forget to record this data. 7. Before we wheel the car, make sure that you mark the starting point of where you want to start, so that we’ll start in the same point. Therefore, the distance is constant. 8. Next, wheel the car. 9. As you wheel it, use a stopwatch to measure how long does the car take to achieve to the ground. 10. Press pause as soon as the car achieves the ground!! 11. Repeat step 5 to 10 to get more data.
apple 2/28/12 9:16 AM Comment: Use the word “reaches”. apple 2/28/12 9:16 AM Comment: Good, nice pictures.
Observations: a) Raw Data
i) Quantitative Angle (°) ±
Time travelled of wheeling the car ± 0.1 s (First Trial)
Time travelled of wheeling the car ± 0.1 s (Second Trial)
The average time ± 0.1 s .
4
2.2
2.1
2.15
7
0.7
0.8
0.75
10
0.6
0.5
0.55
15
0.5
0.5
0.5
21
0.2
0.2
0.2
apple 2/28/12 9:17 AM Comment: Put this in a separate table.
The distance of the starting point (cm)
0.5 0.5 0.5 0.5 0.5
apple 2/28/12 9:17 AM Comment: Just write it once.
ii) Qualitative As you can see from the table above, as we set the number of the angle higher, time taken of wheeling the car is faster. The differences between each experiments that are shown above are not that much. 4° is the starting angle of the experiment and it takes 2.2s for the car to achieve the ground on this angle. 7° is set to be another experiment, and it takes 0.7s for the car to achieve the ground on this angle. As a result, we know that the the dependent variable (Time) decreases as the Independent variable (Angle) Increases. There were sounds produced during the
apple 2/28/12 9:18 AM Comment: This is not the right word – use the phrase “for the car to reach the bottom of the incline”.
experiment. As the angle decreases, the sound of the car wheeling down is really fast. This is another prove that as the height of the angle gets higher, the less time needed to get the car to achieve the ground. b)Processed Data:
Angle (°) ±
The Average time of wheeling the car ± 0.1 s .
4
2.15
7
0.75
10
0.55
15
0.5
21
0.2
apple 2/28/12 9:19 AM Comment: You’re one of the few students who put in uncertainties. Actually it would be higher – around 0.2 or 0.3
Graph of Average Angle vs Time
X-axis → Angle (°) Y-axis → Time (s) Constant distance of starting point → 0.5cm Conclusion: From all the experiments I did above, my hypothesis is proven correct. The graph shows positive correlation. As you can see from the graph above, P1 was at 4 as the angle, and the time was 2.15, which become x= 4, y= 2.15 or (4, 2.15). P2 was at 7 point as the angle, and the time was 0.75, which become (7,0.75). P3 was at 10 as the angle, and the time was 0.55, which become x=10, y=0.55 or (10, 0.55). P4 was at 15 as the angle, and the time was at 0.5 seconds, which become (15,0.5), and p5 was at 21 as the angle and the time was at 0.2 , which become (21, 0.1). Even though there is no best fit line that shown from those x and y intercepts, yet those creates scatter plot which create an up trend, it is clear that ‘the height or the angle of an inclined plane’ is inversely proportional to the time of the car to achieve the ground. As the height of the inclined plane increases, the time travelled of the car to achieve the ground decreases or we could say as the height gets higher, the time travelled of the car to achieve the ground is less needed.
apple 2/28/12 9:19 AM Comment: Use the word support.
The picture above supports the formula below: s= s=
= t= From the formula above, I found out that that and sin
. Yet, as you can see t is
From the formula, I concluded time is less than , and this is why it takes less time for the car to wheel as the angle got increased. Furthermore, when the car is released the gravitational potential energy is transferred into kinetic energy, this is the reason why the car wheel down the inclined plane. My prediction was correct. I anticipated that as the angle of the inclined plane increase, the time would decreases. I am sure and confident it was correct because my graph backs my hypothesis up. I did not spot any oddity in my results. Because, it is proven on my graph that every point on the graph follows the same pattern, which make an up trend. As a result, I concluded that my results seems to be reasonably accurate.
Evaluation:
apple 2/28/12 9:20 AM Comment: Great!
I tried to make my experiment as fair as possible. To a certain area this was achieved, however some aspects on the fairness of the experiment could have been better. The measurement of my experiment were taken using a stopwatch on my iphone. Furthermore, I asked for help to my friend to press the stopwatch. This meant, she might missed a second or two seconds as the car achieve the ground. This could have affected the end recording. On future experiments, I would use a better quality of stopwatch, and use ‘a button’ that could press the stopwatch in a sudden with a fast speed. This made the time to achieve the ground takes longer time, possibly meaning the end recording was not completely fair. Furthermore, a small protractor was used to measure the agree. This meant I had to look closely, and clearly and might loose accuracy. All the readings and numbers were too small, for a big angle that I made on the inclined plane, i felt it was really difficult to get accurate numbers. Also, I had to just use my eyesight as accurately as possible. Next time the angle would have been measured in a big protractor, so that its easier for me to read the numbers, and get an accurate result. Before using a car, I tried to use a ball however I found out that it is hard to measure the time, seeing that the ball goes really fast. I thought using a car is better because it didn’t goes as fast as the ball. Therefore, it is easier for me to record the time. To have made the experiment reliable I should have done several time recordings for each test. At least four recordings for each and from that the average would have given me a reliable set of results. The experiment would also be re run multiple times itself, reason for this this would show how reliable it was. I honestly think that my graph shows my experiment was reliable and well founded, it is proven with the scatter plots which follow an almost exact pattern and create an up trend I am certain that my conclusion is correct because it is the only explanation for the coherent and reasonable set of results. If I would have time to repeat my experiment I am sure I would find a pattern and graph very much the same depending on how well I kept the test fair, accurate, and exact.
apple 2/28/12 9:21 AM Comment: angle
apple 2/28/12 9:21 AM Comment: This is a run on sentence.
apple 2/28/12 9:21 AM Comment: Good.
apple 2/28/12 9:22 AM Comment: This is unnecessary.
Works Cited: "The Effect of Ramp Angle on a Toy Car." EHow. Demand Media, 14 Apr. 2010. Web. 23 Feb. 2012 <http://www.ehow.com/about_6313077_effect-ramp-angle-toy-car.html>. "Physics of Roller Coaster" CEC: Coaster Physics. Web. 23 Feb. 2012. <http://cec.chebucto.org/Co-Phys.html>.
Criterion DE No highlights means the task specific criterion was met. Blue highlights means the task specific criterion was exceeded. Yellow highlights mean you did NOT achieve the task specific criterion. Criterion D Task – Specific Clarification a. focused b. clear
a. Testable (It means the hypothesis CAN be falsified). b. Explain the hypothesis using scientific reasoning.
a. Include all of the relevant variables and name your independent & dependent variables. (Variable Table) b. Mention how to manipulate your independent variable. (method) c. Mention control variables & how you will control them.(method) d. Selects appropriate materials & equipment. (materials) e. Write a clear, logical method. (5-‐6) f. Describe how the data will be collected (using your materials and experimental set-‐up) (method)
3 5
5
5
5
3
5
3
5 5
Objective Level Descriptors
0
1-2
3-4 Descriptors
5-6
D1 State a problem or research questions that is _________
unclear
focused
focused & clear
D2 Makes a hypothesis that is _______ and _______ explain it.
Incom plete/d oesn’t
Testable /doesn’t
Testable /does
(It’s 0 D3 Selects mostly appropriate incomp materials, writes a lete) ___ complete method, mentions _________ variables and how to manipulate them, and ______ describe how data will be collected and processed.
mostly complet e, some, may not
Clear & logical, all, does
Comments on the most relevant of the following regarding the reliability and validity of the method: a. the appropriate selection of/ precision and accuracy of/ uncertainties associated with the measuring instruments, b. the size of the sample/ the sampling techniques/ the number of readings c. if the conditions of the experiment lead to valid data collection d. if the manipulation of the variables was appropriate.
Compares results to theoretical expectations based on explained and cited scientific works.
3-‐ 5
6
D5 Comments on the validity of the hypothesis based on the outcome of the investigation
0 Doesn’t
✓
✓
0 Doesn’t Suggests Suggests D6 ______ suggest some realistic improvements to the method or further inquiry when relevant.
Sufficien tyly
Partially
ts to/ Doesn’t
0 Attemp
D4 ______ evaluate(s) the method in terms of reliability and validity
Your Criterion D Score :6 *Remember, for MYP Science, it’s generally the lowest score that is taken to determine your Criterion Level.
Criterion E Task-Specific Criterion a. Include a minimum of 5 sets of data. b. Take at least two measurements for each change in an independent
≥ 3
Objective Scaffold
Objective Level Descriptors 0
E1 Collects ____ data.
0
1 to 2 Some
3 to 4
5 to 6
Sufficient
sufficient
variable. c. Record a reasonable range of data, and relatively evenly spaced data points. a. Include headings and relevant units for all data. b. Record qualitative data with appropriate descriptions . c. Record only relevant and all relevant data which sometimes includes controlled variable(s). d. For any tables, the IV should be in left column, and the DV in the right column. e. Where appropriate, indicate the source of uncertainty in a measurement f. The number of significant digits should be appropriate to the measuring instrument used. g. Make the degree of precision (final decimal place) the same for each set of raw data.
3
3
3
5
5
5
c. Include a best-‐fit line if appropriate and its equation if it’s appropriate. d. Spread out the range of data points within the graph/chart. e. Include appropriate labels and units for axes on a graph and for parts of a
0
attempts to
correctly
correctly
incompletely
With few errors
Logically & correctly
5
5
a. Take an average of repeated measurements and display in an organized way. b. Include a title that describes both the IV and DV.
E2 _____ record data it in a suitable format.
3
3
3
3
E3 Organizes, transforms and presents data using numerical forms ____.
chart. f. Display key calculations in a clear and sequential manner. Show one calculation example if the calculation is repeated. g. Make the degree of precision for processed data consistent with the raw data. a. From the best-‐fit line/chart, describe the type of relationship (proportional/linear/exponential/no) between the IV and DV. b. Describe how close the points are to the line of best fit.
3
5
3
5
c. Comment on the how close repeated measurements were together.
d. Comment on the number of measurements taken.
5
E4 _________ a trend, pattern or relationship in the data. ________ the reliability of the data
Attempts to identify, Omits
States, Omits
Describes , Comment s on
E5 Draws a conclusion that is _____ the data and ____ a scientific explanation
Inconsistent with, lacks
Consisten t with, lacks
A correct interpretation of, includes
e. Comment on any obvious sources of error during measurement.
f. Use data, such as the equation of the best-fit line, to support your conclusions. b. Explain conclusion using reasoning that draws from accepted scientific theories or principles
3
5
Your Criterion E Score : 6 *Remember, for MYP Science, it’s generally the lowest score that is taken to determine your Criterion Level.