Water Balloon Drop Experiment
By: Ruichao Cui, Andrea Guerra, Susi Bernal
Background Information:
Due to the property of liquid, water’s atoms cannot hold together as tight as solids do. When a water balloon is dropping to the ground, the potential energy will turn into kinetic energy, which is enough to break the balloon. And according to the knowledge that we’ve already known, the higher an object is, the more potential energy it will contain. As more kinetic energy is transferred, the longer the splatters will become.
Statement of the problem: The purpose of this experiment is to find out how different variations of water and corn syrup (different densities) affect the resonant frequency of a wine glass.
Hypothesis: We believe that as the height from ground to where it dropped increasing, the radius of the water splatters will increase too. The heights are used as independent variables, and the radiuses of the water splatters are used as dependent variables. The controlled variables include, but are not limited to the amount of water in each balloon, the horizontal position when each balloon were dropped, and the temperature of the water.
First, we pour water into each balloon with three drops of ink in it, to make it obvious to see when being dropped on the white paper. We measured the weight of the first water balloon by the scale, and recorded the weight. Then add water into another balloon, repeat the procedure with the water running into the balloon using approximately time as the first balloon. Then weigh the second balloon to get to a similar weight. Repeat until collect 20 balloons. Bring all the materials with the water balloons outside to the bleacher. Let one person stand on the highest step, drop the balloon three times and record the radius of each by the rulers . Go down two step and drop another three balloons. Repeat the process four times. Measure the height of each step on the bleacher by letting the person hold one end of the tape measure, and another person read the measurements when it reaches the ground. Repeat for each step, write down the datas.
- tape measure
- rulers
- balloons
- water
- white paper
- ink
- bleacher
- scale
Average weight of the water balloons: 362 kg
|
Height (m) |
Trail 1 |
Trail 2 |
Trail 3 |
Trail 4 |
|
9.24 |
0.42 |
0.37 |
0.41 |
0.40 |
|
8.64 |
0.40 |
0.46 |
0.34 |
0.43 |
|
8.04 |
0.40 |
0.27 |
0.23 |
0.30 |
|
7.44 |
0.22 |
0.31 |
0.29 |
0.27 |
|
4.14 |
0.33 |
0.26 |
0.30 |
0.30 |
summary: Mainly, the radius on the graph is going down as the height decreasing. Except it goes up a little bit when Height is 4.14m, and 8.64m.
As it is shown on the graph, the radius is going down most of the time when the height is decreasing. Except it goes up a little bit when Height is equal to 4.14m, or 8.64m.
The hypothesis of this experiment is that we believe, when other variables are controlled, as the height from ground to where it dropped increasing, the radius of the water splatters will increase too. But the result could not prove our entire hypothesis statement because the radius weren't decreasing all the time, it went up instead.
The energy stays the same all the time, it just transferred from the form of potential energy into kinetic energy. While the weight of the balloon and the force of the gravity has stay the same all the time, then the higher a balloon is, more potential energy it would have. As the balloon approaching the ground, more and more energy turned into the form of kinetic energy. Water cannot hold itself together tightly, so enough force from the water will break the water balloon due to the kinetic energy it contains. More force will push the water splatter further, and could make longer radius.
There are several factors in the experiment might have certain effect toward the datas, it can also conduct errors. The main factor is the fact that the water balloons are not identical, even with the same size, they have a little bit of quality difference, some are thicker than others. This caused some of the waterballoons wouldn't pop not matter what the height is. So it makes sense if the radius of the water splatters are different because the water already consumed different amount of forces in order to broke the balloons. Another factor is the way of measuring the length of the radius in each water splatter's mark. Because we are using a middle point and set up an average point to connect with the center to make the radius, so there might be some inaccuracies during the averaging process.
If we can do this experiment all over again, there are some ways to improve our results. We will do more trails so we can balance out the difference of the balloon qualities. Also, if we have enough time, we can measure couple longest and shortest radius in one water splatter figure. Then averaging the several radius to get only one number, which can be accurate and can show the differences clearly.
Reference: http://www.thescienceforum.com/chemistry/2847-why-does-water-splash.html
http://www.thescienceforum.com/chemistry/2847-why-does-water-splash.html This site related balloons to ungulates
http://spaceflightsystems.grc.nasa.gov/WaterBalloon/ Popping balloons in low-gravity
http://blogs.yis.ac.jp/19chene/2013/02/13/our-forces-design-task-from-planning-to-starting-our-experiment/ Another water balloon drop experiment
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p066.shtml#procedure A way to measure the water splash
http://physics163projectstancik2012.wikispaces.com/LeinbachHaddad How temperature has an effect on dropping too