A World in a Bottle

Lab Report Guiding Question: How do organisms survive in a closed ecosystem? Hypothesis: I am hypothesizing that the plants will grow around 5 inches in 10 days. My hypothesis were almost correct. The plant grew 4 inches in 11 days. Materials: • Soil • Sand • Cotton • Seeds • Water • Plastic bottles • Moss Process: First my group and I have got two plastic bottles and cut the top of the bottle and put soil in the bottle, afterwards, we have planted seeds in the soil and sprinkled some water so it can grow faster. In the other bottle we cut the bottle, put the soil, planyed seeds and we have put cotton . We did this so we can see which one will grow faster and better. Variables: In our lab the controlled variables were, the soil, the seeds , and the water. The manipulated variables were cotton, and moss. Data collection: Table Data collection: In our lab we have measured the height of the plant daily, so that we can see how much did the plant grow from the day before we measured in inches. Our controlled variable was the height. Content Review In this lab the biotic factors were the seeds ,the soil , water. The abiotic factors were: cotton, moss, and sand. 2. The factors all have entered the terrarium, cotton for example helped us by growing the plants much faster. 3. A plant eating insect would be able to survive but for a short period of time because it will eat the plant in just few days. 4. It differs by: we planted the plants in a bottle, and we used cotton and moss and sand which differs a lot from the ecosystem in the world. Plants are mostly planted in soil in the ground. Conclusion: The Planting in a bottle with abiotic factors proved true. This type of planting worked a great deal. The plants grew over 10 inches this proved that this method could be used for a shorter period of time, because the roots wont have any more room to grow in the bottle. Further Inquiry: I am questioning, would the plants able to survive more time in the bottle even though their roots are getting bigger.

Sound Waves Lab Report

Luka Ilic 5/25/2012 Mrs. Medenica Science International School of Belgrade Sound Waves Lab Report Guiding Question: Through which objects do the sound waves travel faster or slower, do the vibrations through an object depend on the density of the object? Hypothesis: The sound will travel faster through less dense objects than through the denser objects, causing bigger and smaller vibrations, respectively. Variables: Controlled variable will be the tuning fork. Manipulated variable will be the various types of solids through which the sound will be traveling, causing vibrations. The Responding variable will be the vibrations that have traveled through the objects. Materials • Tuning fork • Various surfaces which will be tested. Procedure: First I will have to get my materials. This includes the tuning fork and the surfaces to be tested. Tap the tuning fork on various surfaces such as a desk, wall, chair, locker, etc. Measure the time of the vibrations in the tuning fork. Record and analyze the data of vibrations distributed through the objects listed above. Data Table Data Analysis: During Experimenting I have noticed that the less dense an object is he easier the vibrations travel through it. On the other hand, vibrations travel slower through the denser objects, thus, the vibrations are more difficult to hear. I have recorded how much tome does it take for a vibration to travel through the objects listed above, and can say that the vibrations have traveled the longest through the metal plate. This is because the experimented surface in this case the metal plate has a very low density. While, the vibrations traveled the fastest through plastic. Since the experimented plastic was thick, the vibrations stopped traveling at 12 seconds. What I have noticed is that the thicker the object, the slower the vibrations will travel through it. I also recorded the types of vibrations. The diminishing vibrations were fading away all the time, the sustain diminishing vibrations were staying on a certain point for a small period of time but again afterwards started fading away. Further Inquiry: During experimenting I came up with some questions related to this experiment. I thought if vibrations could be measured, in other worded if there is a typical method that is used for measuring vibrations. Regarding this I also came up with a question of how do vibrations stop and why do they stop at a certain point. Conclusion: As a result of this. Vibrations are basically, sound waves that can travel through any object. In this experiment the manipulated variable were the various objects that the tuning fork was tested on. Therefore, this meant that the solids were not all having the same amount of mass; instead, all of the solids that have been tested had different amounts of mass in them. This is why I had to measure the time of the vibrations traveling through an object. Vibrations ca travel fast and make big vibrations through an object, or they could travel slowly and make very little vibrations through an object. All of the depends on the density of an object. Since the vibrations are sound waves they will take up all of the area that is given to them to distribute their wave’s trough, just like water waves.