Group+2+(Tony's+Team)



__Group 2's Lab-(Tony, Ljuan, Ramsey,Cat)__

__Abstract__ 

In this lab, we will be creating a multi-mass system connected and suspended from an Atwood machine and hanging from a table. An Atwood machine is a system where two masses are connected by a cord and on a pulley system. We put equal amounts of paper clips on each weight, and then we transfer one paper clip at a time to the other weight until one side descends with constant velocity. Constant velocity means no acceleration and the net forces equal zero, so this is used to calculate the frictional force of the pulley on the weights. The acceleration throughout the entire system is the same; the force has the same value on the cord anywhere in the system. Next we transfer two paper clips at a time so that one mass weighs more than the other, and there is a net force. The net force causes acceleration on both weights, and it increases with each transfer of two paper clips. We time each trial after every transfer, for five trials. We then use our data to compute the experimental value of acceleration due to gravity, and compare it to the accepted value.

__Introduction__

In an Atwood's machine, the difference in weight between two hanging masses determines the net force acting on the masses. For this particular lab, each hanging mass was 200 grams. Unequal amounts of paperclips were added to both sides to create a difference in weight. The difference in weight causes both hanging masses to accelerate when the lighter mass is released from the floor; the heavier mass is accelerated downward, and the lighter mass is accelerated upward. The overall purpose of the Atwood Machine lab is to study Newton's Second Law of Motion, F=ma. This lab is important because it is vital to understand the relationship between the three factors, mass, acceleration, and net force. This lab focuses on how mass affects the net force acting on a system, which in turn, affects the acceleration of the system.

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__Procedure__ __1. On both sides of the Atwood Machine, hang one 200 gram weight with 15 paper clips attached to each weight. 2. Transfer two paperclips from one weight to the other until the system moves smoothly in order to overcome friction. 3.With the ascending weight on the ground, give the descending weight a large enough tug to get the system going smoothly. 4.Find the amount of time it takes for the ascending weight to reach the top from the moment it leaves the ground. 4. Repeat this procedure of moving two paper clips from the ascending side to the descending side until none are left on the ascending side. 5.Find the acceleration in the system using F=ma 6. Graph acceleration vs. (m1-m2)/m1+m2 7.Find the value of gravity in this system and compare it to the actual value of gravity.__

__Data Table and Graph__ m/s² ||
 * = Trial # ||= Mass Transferred (g) ||= Total Mass Difference (g) ||= Net Force (N) ||= Time 1 (sec) ||= Time 2 (sec) ||= Time 3 (sec) ||= Average Time (sec) ||= Experimental Acceleration
 * = 1 ||= 0 ||= 10.5 ||= .0657 ||= 12.41 ||= 12.31 ||= 13.02 ||= 12.58 ||= .016 ||
 * = 2 ||= .84 ||= 12.18 ||= .148 ||= 8.19 ||= 8.44 ||= 8.32 ||= 8.32 ||= .036 ||
 * = 3 ||= .84 ||= 13.86 ||= .2941 ||= 6.23 ||= 5.79 ||= 5.75 ||= 5.92 ||= .071 ||
 * = 4 ||= .84 ||= 15.54 ||= .4742 ||= 4.81 ||= 4.59 ||= 4.64 ||= 4.68 ||= .114 ||
 * = 5 ||= .84 ||= 17.22 ||= .6348 ||= 4.05 ||= 4.12 ||= 4.01 ||= 4.06 ||= .152 ||



Conclusion 1. The advantage of transferring mass from one to another is that we keep a constant total mass in the system. When dealing with tension and F=ma,the force is transferred though tension and we have easier calculations.

2. The Difference in our experimental and calculated values for acceleration could be due to an inconsistency in the amount of initial force we used to get the system moving, also the our timing wasn't perfect. Another source of error could be a miscount for the number of paperclips which would change our mass.

3.Our Tension is 1.967N. Which would be the same on both sides because Tension Is a transfered force. The weight of one side is equal to the tension on the other side.

4. The pulley should be as light as possible because a heavy pulley adds mass/friction which would make the tension on both sides not necissarily the same. A lighter pulley makes the transfered tension as close to equal as possible. So the calculations are a lot easier.

The atwood machine Demonstrates unifrom acceleration. our data helps show the relationship between F=ma and how they have direct and inverse relationships.