Megan,+Niko,+Kristin+Accelerated+Motion

=Accelerated Motion= 10/27/09


 * Participants**: Megan Fucci, Niko Pearson, Kristin Kozlowski
 * Purpose**: To determine the acceleration of (1) a hover-puck traveling across a flat surface (2) a free-falling 1 kg mass and (3) a free-falling 100g mass.

HOVER-PUCK- POSITION AND VELOCITY GRAPHS 1KG MASS- POSITION AND VELOCITY GRAPHS 100G MASS- POSISTION AND VELOCITY GRAPHS
 * Brief Description of Experiment**: For this lab we used the tape timer to record the position of a free-falling object or something traveling across a flat surface every sixtieth of a second. The hover-puck, a 100g mass, and a 1 kg mass were the studied objects. After we had collected our data we measure the distance between the initial point and every other point on the strip. To graph our information we entered it into logger pro with point number and position. From there we created a new two new calculated column to measure velocity and time. Finally, we calculated the velocity for each object by measuring the slope of each set of graphed data.
 * Data**:
 * Sample Calculations:**
 * //Velocity//

//Time// || V = change in position / time (seconds)

T = Point Number / 60 ||
 * Results**: The acceleration of the 1 kg free-falling object was 741 cm/sec. The acceleration of the 100 g free-falling object was 744.3 cm/sec. The acceleration of the hover-puck was -6.799cm/sec.
 * Lab Questions**:
 * 1) **__Which objects that you studied were clearly accelerating? How can you tell by looking at the motion of the objects? How can you tell by looking at the position vs. time graph? How can you tell by looking at the velocity vs. time graph?__** The 100g and the 1kg masses were accelerating at fairly steady rates. There were slight changes in the rate of acceleration when they fell, but nothing drastic. After releasing the mass (for both masses) it hung for a brief moment in the air before falling at a gradually increasing velocity. This is expressed by the slope's (more or less) constant increase on the position and velocity vs. time graphs for both masses.
 * 2) **__Which objects that you studied were not accelerating/ were accelerating slightly? How can you tell by looking at the motion of the objects? How can you tell by looking at the position vs. time graph? How can you tell by looking at the velocity vs. time graph?__** Of the objects that we studied the hoverpuck was alone in the fact that it did not accelerate (at least not significantly). When we pushed it across a table, the hoverpuck appeared to move at a constant velocity. This is represented on the position vs. time graph by a straight line instead of a parabola (which represents a gradual increase in velocity). On the velocity vs. time graph it is represented by a line that is, for the most part, straight. There are consistent dips of equal size, but considerng that the graph has been scaled down and the line follows the same general pattern, these can be ignored.
 * 3) **__What was the value of the acceleration of the 1 kg object? Can you find a relevant value to compare this to for a "free-falling object" near the surface of the earth? How do your values compare (% difference)? Follow-up: If you also did a 100 g object, what was the acceleration and how does this compare (% difference)?__** The acceleration for the 1 kg free-falling object was 741 cm/sec. When compared to acceleration due to gravity the percent difference is -24.3%. The acceleration for the 100 g object was 744.3 cm/sec. The difference between the 1kg free-falling object and the 100g free-falling object is -0.4%.
 * 4) __**What is meant by negative acceleration?**__ Negative acceleration means the velocity is decreasing. The object is going a smaller distance in relation to time.

This experiment produced a valid reproducible result. Our data matches what we know about acceleration, position, time and velocity. We know as an object free-falls to the Earth it gains velocity, or accelerates due to gravity. The push given to the hover-puck could be fairly inaccurate due to the force that was used. The force could vary and therefore give different results. When gathering the data for the 1kg free-falling object the measurements were only taken by distance between each point and not from the starting point. This could cause inaccurate data because there could easily be addition errors and more. Also, when reading the data on the strips of tape the points were fairly light and hard to read. This could cause additional points that seemed to appear but were actually not present and also the loss of actual points. Also, we assumed that the tape timer did in fact measure 1/60th of a second, but we never actually checked that. If there was any flaw in the tape timer that would have effected our position data, and then alter our velocity data.
 * Conclusion:**