Bret+and+Tom+Lab

Bret and Tom Lab

Objective: What is the acceleration of a falling body?
Hypothesis: If we run a spark tape through a spark timer and there is a mass is attached to the tape and dropped downward starting at rest, then you can find the acceleration of gravity by using a position-time graph. this is procedure not a hypothesis

Materials: Ticker Tape Timer, Timer tape, Masking tape, Mass, clamp, meterstick.

Procedure:

1. Clip a spark timer to a cabinet and obtain enough ticker tape to reach the floor (approximately 2 meters). 2. Set ticker tape timer to 60 Hz. 3. Drop mass from ticker tape timer. 4. Measure distance between all of the dots on the ticker tape. 5. Record data. 6. Create a Position vs. Time graph from the data collected. 7. Find the acceleration of the falling body.



**__Calculations__**







where is class data?



Discussion Questions: 1. Does the shape of your graph agree with the expected graph? Why or why not? Yes the shape of our graph agrees with the expected graph. According to our R2 value which measures accuracy of your results and how many points you have the expected trend line, we were real accurate. Our R2 value was .9994, which is approximately equal to 1, which would be 100%. 2. How do your results compare to that of the class? (Use Percent difference to discuss quantitatively.) Compared to the class average, our results were not too far off. Our results were 5.51% off of the class average which is a fairly low percent difference. The class average was smaller than the theoretical value because of some outliers, which is why our average is further from the class average than the theoretical value. 3. Did the object accelerate uniformly? How do you know? No it did not, it accelerated at about 9.2 m/s2 which is below the uniform acceleration of an object which is 9.8 m/s2. This is known by finding the equation of our line. Even though we converted our numbers to cm, the leading coefficient, was 461.29, which according to (insert equation) is half the acceleration. So we doubled the leading coefficient and converted it back to meters leading us to find the acceleration. just because results are lower doesn't mean not uniform. What does it mean to be uniform? 4. What should the velocity-time graph of this object look like? The velocity- time graph of this object should start at (0,0). It also should have a negative slope of -9.2 per 1 second. good! The negative slope comes from the object starting at rest and then falling downwards. The slope is constant because that is the acceleration of the object. The velocity time graph would have a straight diagonal line, ending in a large negative velocity. 5. Write down the expected equation of the line from this v-t graph (use specific information from your x-t graph). y=-922.58x. X is equal to the amount of time in seconds, and Y is equal to the velocity in cm/ s. I converted the acceleration back to cm/m2 because it is more suitable to our data. 6. What factor(s) would cause acceleration due to gravity to be higher than it should be? Lower than it should be? It could be higher than it should be if when the mass was being dropped, an extra push by the person's hand could have increased the speed and made the object accelerate higher than usual. As exhibited in ours, the mass would be lower as exampled by other forces. <-- not sure what you are trying to say here. --> Since the ticker tape was attached to the weight, it slowed the tape down a little bit. The ticker tape was being hit by the spark timer which caused some deceleration. It was slowed down by the tape sliding up against the cabinet while being fed into the spark timer. After being slowed by a few different things, then it would lower the acceleration.

Conclusion:

We achieved the purpose of this lab, which was to find the acceleration of an item in freefall. We were also fairly close to the theoretical acceleration rate, 980 m/s2. Our calculated acceleration based on the results from our drop was 922.58m/s2 A possible source of error in our lab could have been the friction created when the tape rubbed up against both a cabinet door and the inside of the ticker-tape timer. One way to minimize this percent error would be to run the tape straight through the timer rather than letting it arch over the top of the cabinet before going through the ticker-tape timer. As far as the friction created by the timer goes, it wouldn’t be possible to eliminate that unless a different measurement method was used. <span style="background-color: #ffff00; font-family: 'Comic Sans MS',cursive; font-size: 110%;">like what?