rachel+and+emily

=What is the Acceleration of a Falling Body?= By Emily Burke and Rachel Caspert Due Date: September 27, 2009

To determine acceleration of an object due to gravity. (What is the acceleration of an object in free fall?)
 * Purpose**

If we attach a weight to the end of the ticker tape and let it freely drop, then the acceleration of the weight will be 9.81 m/s^2 (981 cm/s^2).
 * Hypothesis**

- ticker tape timer - timer tape - masking tape - mass - meter stick - clamp
 * Materials**

What is the acceleration of a falling body? this is same as purpose
 * Objective**

1. Attach the spark timer to a cabinet with a clamp. 2. Put the spark timer tape through the spark timer, making sure it will flow nicely through the spark timer. 3. Using the masking tape, attach the 100g weight to the spark timer tape at the end. 4. Drop the weight and observe the tape going through the spark timer, making sure it flows smoothly. 5. After receiving the dots made by the spark timer, get a meter stick and record the length of each dot from the initial starting point. 6. Put the data into excel and create a graph. 7. Calculate the value of "g" using the data.
 * Procedure**

need units in heading and data tables need to go BEFORE graph that uses the data.
 * Graphs and Data**

y=375.28x^2 - 13.455x y=Ax^2 + Bx y=d x=T d=AT^2 + BT d=1/2aT^2 + ViT
 * Calculations**

A=1/2a A=375.28=1/2a a=750.56 cm/s^2

Percent Error (Expected-Observed)/Expected * 100 (981-750.56)/981*100 23.49% Error

Yes, it's a polynomial graph that shows the object is increasing and away. It starts with a slope close to zero (which means the initial velocity was zero) and then curves up, increasing the slope (which means increasing the velocity). Although it had a very similar shape, I think our graph was a little more shallow than the actual graph would be of an object truly in free fall.
 * Discussion Questions**
 * 1) Does the shape of your graph agree with the expected graph? Why or why not?

missing Yes, the object did accelerate uniformly because the graph shows a positive curve where speed picks up. We know it accelerates uniformly because it increases exponentially from the looks of our graph.
 * 1) How do your results compare to that of the class? (Use Percent difference to discuss quantitatively.)
 * 1) Did the object accelerate uniformly? How do you know?

It would have a line in the positive region of the graph starting at (0,0) with a positive slope moving up and to the right. what should slope be?
 * 1) What should the velocity-time graph of this object look like?

y = 750.56x + 13.455
 * 1) Write down the expected equation of the line from this v-t graph (use specific information from your x-t graph).

If acceleration due to gravity were higher than expected, there must have been some force pulling it down from the bottom, maybe a person yanking it down faster so the object would no longer be considered in free fall. If the acceleration were lower (which ours was), there was something at the top holding it back, therefore not fully allowing the weight to be in true free fall. As the ticker tape went through, we loosely let the tape glide through our hands so it wouldn't twist, unfortunately slowing down the actual dropping process. good
 * 1) What factor(s) would cause acceleration due to gravity to be higher than it should be? Lower than it should be?

Although our experiment was not exactly accurate, we got to understand the meaning of where the formula of acceleration due to gravity came from. Since we used a ticker tape and our hands, our results were not what we had wanted so our hypothesis didn't match our results, but the concept was learned and with the all of the data from the class the results were more accurate. We had a 23.49% error, so if we had time we would have dropped the weight a few more times to lower that percentage and get to truly experiment with an object in free fall. As mentioned in the discussion questions, our acceleration was a little lower than what was expected due to our hands getting in the way and stopping the weight from freely falling down. This problem is hard to fix to get a perfect result because if we didn't guide the tape through, it might have turned and possibly missed points and or slow it down. This lab is very prevalent in real life because it has to do with gravity. Gravity's the force that keeps everything in place and the reason why when we drop the weight from the counter it doesn't float in mid air. Gravity seems to be an extremely important principal in future physic lessons and is going to be necessary to understand.
 * Conclusion**