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- 1. PHYSICS INVESTIGATORY PROJECT ELASTICITY VS TEMPERATURE Submittedby : P.ABISHEK Class & Sec : 12-B2
- 2. ACKNOWLEDGEMENT The successful completionof any task would be incomplete without mentioning the names of those persons who helped to make it possible. I take this opportunity to express my gratitude in few words and respect to all those who helped me in the completion of this project. It is my humble pleasure to acknowledgement my deep senses of gratitude to my Physics teacher,Mr.MARI AYYAPPAN for his valuable support, constant help and guidance at each and every stage, without which this project would not have come forth.
- 3. CERTIFICATE This is tocertify that , this physics investigatory project on the topic “ELASTICITY VERSUS TEMPERATURE” has been successfully completed by P.ABISHEK of class XII B2 under the guidance of Mr. MARI AYYAPPAN (P.G Physics) at Velammal Vidhyashram , Surapet for the partial fulfillment of Physics Practical at the curriculum of AISSCCE - CBSE, New Delhi during the academic year 2019-2020. Teacher in - charge Signature of External Examiner Signature of Internal Examiner Signature of Principal
- 4. CONTENTS: 1. Basic knowledge 2.Abstract 3. Purpose 4. Hypothesis 5. Materials required 6. Procedure 7. Observation 8. Conclusion 9. Bibliography
- 5. Basic knowledge In physics,elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate forces are applied to them. If the material is elastic, the object will return to its initial shape and size when these forces are removed. Hooke's law states that the force should be proportional to the extension. The physical reasons for elastic behavior can be quite different for different materials. In metals, the atomic lattice changes size and shape when forces are applied (energy is added to the system). When forces are removed, the lattice goes back to the original lower energy state. For rubbers and other polymers, elasticity is caused by the stretching of polymer chains when forces are applied. Perfect elasticity is an approximation of the real world. The most elastic body in modern science found is quartz fibre and phosphor bronze, but even this is not a perfect elastic body. The perfect elastic body is an ideal concept only. Most materials which possess elasticity in practice remain purely elastic only up to very small deformations. In engineering, the amount of elasticity of a material is determined by two types of material parameter. The first type of material parameter is
- 6. called a modulus,which measures the amount of force per unit area needed to achieve a given amount of deformation. The SI unit of a modulus is the pascal (Pa). A higher modulus typically indicates that the material is harder to deform. The second type of parameter measures the elastic limit, the maximum stress that can arise in a material before the onset of permanent deformation. Its SI unit is also the pascal (Pa). Abstract The objective: The purpose of my project is to determine the effect of different temperatures on the elasticity of rubber bands. Rubber comes from and is collected in one way. Natural rubber is taken from a tree called "Hevea brasiliensis" which originated in the Amazon rain forests. In 1876 H.A. Wickham brought seeds of the Hevea tree from Brazil to Kew Gardens, which was near London. The seeds were then given to India, Ceylon, British Malaya, and other countries. The tree takes about five years to grow from a seedling to a point that it can start to produce rubber. It has a lifespan of about 25 to 30 years.
- 7. Purpose To compare theheight of a rubber band when stretched before and after exposed to various temperatures. Hypothesis I hypothesize that if the rubber band is stretched after being exposed to hotter temperatures, the height of its stretch will be bigger than after it has been exposed to colder temperatures.
- 8. Materials • Rubber bands(selectumbrand) • Weights • Hot water • Pot • Refrigerator • Ruler (30 cm) • Hook Procedure 1. Take out rubber band from the box and group them into three for three trials at each temperature. 2. Place the first three rubber bands in a room temperature for 10 minutes. This will be the main temperature for the experiment. 3. Take one rubber band from the three and cut it at a point. 4. Take a hook and attach it to the edge of a surface with tape so that it does not fall. 5. Tie one end of the rubber band and attach it to the hook and attach the other end to a weight. 6. Wait till the band stop moving and is still, than measure the band after stretched, with a 30 cm ruler.
- 9. 7. Record theheight and write it on a sheet of paper so that you do not forget. 8. Then take out the next two rubber bands from the room temperature setting and repeat the steps. 9. Repeat steps 2 and 8 for the rubber bands in boiling water and the freezer. 10. Record the average heights of the rubber bands for all three trials for each temperature setting. 11. Compare the average height of the bands when they were placed in a refrigerator and boiling water to the bands placed in room temperature. 12. Observe what difference you see in the heights stretch of the rubber bands for all of the above trials.
- 10. Observations Conclusion In conclusion, rubberbands when placed in warm temperatures stretch more. But when a rubber band is placed in cold temperatures, the rubber band will stretch less. I hypothesized that the rubber bands would stretch more when heated and less when cooled. That is exactly what happened. The average height of the bands when heated was much higher than when they cooled.
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