Balloon+Drop+Lab


 * Balloon Drop LabLab Title:** Balloon Drop


 * Primary Authors:** Alli, Jonathan, Kevin

Our goal as a class was to make sure our water balloons would hit our teacher when we dropped them from the bleachers.
 * Goal:**

Although at first it may seem like a very simple task, accurately dropping a balloon on somebody's head is far from that. It is a task that heavily relies on physics and the principles of kinematics. It is almost impossible to hit somebody on the head with a water balloon on the first try without using physics. This lab cannot be done by just guessing. It requires knowledge of kinematics along with a lot of teamwork within the class. The idea is that while our teacher is walking under the bleachers, someone is waiting at the top for her to get to a certain point before they let go. We measured a certain distance away from where the water balloon would drop and used her constant velocity along with the time it takes the balloon to fall to find out when we need to drop the water balloon. Ideally, we would like to hit our teacher with the water balloon on the first try, but we were allowed up to 3 trials to accomplish the task.
 * Introduction:**

Balloons Tape-measure Stop-watch Calculators
 * Required Materials:**

Height of Bleachers: 9.1 meters Teacher Height: 1.59 meters Displacement: 7.51 meters Acceleration of Free-Falling Object: 9.8 meters/sec/sec
 * Data:**

Primary Kinematics Formula: Δx = Vot + (1/2)at^2

Using this information, we can figure out exactly how long it would take for a water balloon to drop 7.51 meters and hit our teacher on the head. The only thing that we had to do was plug these values into the kinematic formula (remembering that the initial velocity is 0):

7.51 = (0)t + (1/2)(9.8)t^2 7.51 = (1/2)(9.8)t^2 1.53 = t^2 t = 1.24 seconds

As a class, we decided the easiest way to accomplish this task was to split up into groups. One group went up to the top of the bleachers to drop the balloon. Another group was underneath the bleachers with a tape-measure while the last group started a long distance away from the bleachers with another tape-measure. We thought that the easiest way would be to have our teacher start far away from the bleachers and walk at a constant speed. One of the groups would use the tape measure and a stop-watch to find out how long it takes for her to walk 10 meters and find out her speed. While our teacher is still walking at a constant speed, those student would quickly plug in the numbers into the formula and yell out how far away our teacher has to be from the bleachers when we drop it. Our data was as follows:
 * Method:**

After finding the time, we can use our teacher's speed to find out how far away she needs to be when we drop the balloon. In order to do this, we had her walk 10 meters and we found out how long it took her to walk that distance. It turned out to be 7 seconds on the dot. Using that information, we calculated the speed.

10m/7s=1.43m/s

Since we know how long it takes for the balloon to drop 7.51 meters and how fast our teacher is moving, we can calculate how far away she has to be from the bleachers when we drop it.

1.43m/s*1.24s=1.77m


 * Conclusion:** For two out of the three trials we didn't have any significant human errors. After getting a better idea about when we needed to drop the water balloons, our last trial had an human error. The water balloon was dropped a little too far away, just missing our teacher. A couple variables that we couldn't really account for were: the same speed between each trial, air resistance, and the reaction time of the person who dropped the balloon. If we were able to use a machine that could keep a constant speed between trials, and/or having a timer to release the balloon at a specific time while using air resistance to find exactly when it would hit our teacher, then we would have had a much smaller area for error.

Movie Time: Here is the following movie that was put together using clips from all 3 trials! For the protection of the students, names were not used in the making of this film.

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