Chris+and+Richie

Lab 3: What is the acceleration of a falling body?

PARTNERS: Chris Hallowell, Richie Johnson

OBJECTIVE: What is the acceleration of a falling body?

MATERIALS: Ticker Tape Timer, Timer Tape, Masking Tape, Weight, Clamp, Meterstick

PURPOSE: The purpose of our experiment is to determine the acceleration of the free-falling weight using an excel sheet as well as a graph to determine our solution.

HYPOTHESIS: We believe that the acceleration of the falling weight will be a little less that 9.8 m/s^2 because of the air resistance present when performing the experiment. We know that gravitational acceleration is 9.8 m/s^2 with no air resistance, therefore our results should be slightly less that 9.8 m/s^2.

PROCEDURE:


 * 1) Clamp the ticker tape timer to the cabinet door.
 * 2) Acquire a piece of ticker tape less than the length of the door or about two meters.
 * 3) Run the ticker tape through the timer and tape it to a 100 gram weight.
 * 4) Set the ticker tape timer to 60Hz and let the weight drop.
 * 5) Count the dots on the ticker tape and measure how far away they are from each other.

DATA TABLE:
 * Dot Number || Time (s) || Position (m) ||
 * 1 || 0.0167 || 0.0091 ||
 * 2 || 0.0333 || 0.0130 ||
 * 3 || 0.0500 || 0.0198 ||
 * 4 || 0.0667 || 0.0251 ||
 * 5 || 0.0833 || 0.0349 ||
 * 6 || 0.1000 || 0.0461 ||
 * 7 || 0.1167 || 0.0597 ||
 * 8 || 0.1333 || 0.0756 ||
 * 9 || 0.1500 || 0.0932 ||
 * 10 || 0.1667 || 0.1114 ||
 * 11 || 0.1833 || 0.1313 ||
 * 12 || 0.2000 || 0.1538 ||
 * 13 || 0.2167 || 0.1774 ||
 * 14 || 0.2333 || 0.2033 ||
 * 15 || 0.2500 || 0.2299 ||
 * 16 || 0.2667 || 0.2600 ||
 * 17 || 0.2833 || 0.2911 ||
 * 18 || 0.3000 || 0.3242 ||
 * 19 || 0.3167 || 0.3601 ||
 * 20 || 0.3333 || 0.3981 ||
 * 21 || 0.3500 || 0.4388 ||
 * 22 || 0.3667 || 0.4831 ||
 * 23 || 0.3833 || 0.5303 ||
 * 24 || 0.4000 || 0.5822 ||
 * 25 || 0.4167 || 0.6393 ||
 * 26 || 0.4333 || 0.6982 ||
 * 27 || 0.4500 || 0.7610 ||
 * 28 || 0.4667 || 0.8262 ||
 * 29 || 0.4833 || 0.8941 ||
 * 30 || 0.5000 || 0.9618 ||
 * 31 || 0.5167 || 1.0321 ||
 * 32 || 0.5333 || 1.1049 ||
 * 33 || 0.5500 || 1.1800 ||
 * 34 || 0.5667 || 1.2562 ||
 * 35 || 0.5833 || 1.3338 ||
 * 36 || 0.6000 || 1.4132 ||
 * 37 || 0.6167 || 1.4949 ||
 * 38 || 0.6333 || 1.5777 ||
 * 39 || 0.6500 || 1.6640 ||
 * 40 || 0.6667 || 1.7524 ||
 * 41 || 0.6833 || 1.8441 ||

POSITION-TIME GRAPH:

CALCULATIONS:

DISCUSSION QUESTIONS: 1. Does the shape of your graph agree with the expected graph? Why or why not? Yes, the shape of our graph does agree with the expected result because in our experiment, the velocity of our falling object was getting larger. Our graph shows that the velocity started around 0 m/s and increased as the object fell. We expected our graph to curve positively because of the consistent acceleration of the object.

2. How do your results compare to that of the class? (Use Percent difference to discuss quantitatively.)

Compared to the average data found by the class (8.74 m) our data (8.307 m) was only 5% less than what the rest of the class found. This is means that our data was relatively close to what our other class mates found.

3. Did the object accelerate uniformly? How do you know? Yes, the object did accelerate uniformly due to the shape of the graph. Our graph had a consistent curve therefore we can say that the acceleration was uniform throughout the fall. If there had been a spot where the graph either flattened out or rose quickly, we would have known that there was a change in acceleration.

=
A factor that would cause the acceleration t be higher than the acceration due to gravity is if the weight was given a push or if it was even thrown to the ground. A factor that would cause the acceleration to be less than that of gravity is the friction that the tape encounter after going through both our hards and the ticker tape timer. ======

CONCLUSION:

After performing our experiment, the results showed that our original hypothesis was slightly incorrect. We believed that the acceleration of our falling object would be a little less than 9.8 m/s^2 and after performing the lab, our acceleration was 8.3072 m/s^2. Although, after determining our percent error and percent difference compared to the class average, the results were 4.952% and 5.078% respectively. This shows that we were not far off from what the rest of our class observed in their experiments as well.

In our hypothesis, we believed that the error in our experiment would come from he air resistance as the object was rapidly falling to the ground. After performing the experiment, we learned that the previous assumption was incorrect. The error in our experiment could have came from the friction that occurred when the tape came in contact with our hands as we were feeding it through the ticker tape timer. Friction also occurred when the tape came in slight contact with the timer itself. Another source of error could have been the tape being slightly twisted as it was coming through the timer. Finally, the last form of error could have occurred when we were measureing the distance on the tape between dots. These are all possibilities that could have slowed down our object, therefore lowering the acceleration.

In the future, this experiment could have been performed with more precision by using a machine to feed the tape through the timer to minimize the contact with our hands as well as lower the possibility of twisting the tape. Another way to minimize the error would have been to use a more precise measuring tool to measure the distance between dots. The meterstick was useful but the process could have been improved with a more stable device.

nicely done! very complete and great results.