Investigate the Strength of Straw Essay Example

Investigate the Strength of Straw Essay Example Investigate the Strength of Straw Essay Investigate the Strength of Straw Essay The purpose of this experiment is to investigate the relationship between the number of straw used and the strength of straw when weigh is constant. First and foremost, experiment was started by using one straw. The initial reading from the pointer was taken before the masses were suspended. Then, the slotted mass carrier together with constant masses in detail, 1000g, was suspended at the straw. As the result, the pointer will give the new reading. That reading was taken as the final reading. Step 2-5 was repeated for vary number of straws. Based to the theory, when we stretched it, we are trying to overcome the intermolecular bonds between the molecules. At the same time we are also trying to change the position of molecules that are held together by the intermolecular bonds. With vary number of straws; its strength also will increase. What we realized after conducting this experiment is once the number of straw increases as the result the length of stretched straw will decrease due to the constant weigh. While, when the length of stretched straw decreases; the strength of straw will increase. This is mean; the number of straw used is proportional to the strength of straw when weigh is constant. Actually we decide our hypothesis based to the theory below; While for the straw itself, when we stretched it, we are trying to overcome the intermolecular bonds between the molecules. At the same time we are also trying to change the position of molecules that are held together by the intermolecular bonds. With vary number of straws; its strength also will increase. Theory: Term such as strength, stiffness and toughness are used in a special way by physicists. Strength refers to the quality or state of being strong, in particular the capacity of an object or substance to withstand great force or pressure. While stiff or stiffness means small strains for large stresses (large Young modulus); not stretchy or bendy. Tough or toughness means undergoes considerable plastic deformation before it breaks. Consequently, tough materials absorb a great deal of energy before they break. In the experiment, when choosing a material it is always important to consider how the material behave under the conditions in which it will be used. For example, concrete is very strong under compression, but is weak in tension, where it breaks by brittle fracture as cracks open up. Aluminum has a similar stiffness to glass, but glass is usually brittle and shatters for very small strains whereas aluminum undergoes plastic deformation before breaking. In other word it is tough. While for the straw itself, when we stretched it, we are trying to overcome the intermolecular bonds between the molecules. At the same time we are also trying to change the position of molecules that are held together by the intermolecular bonds. With vary number of straws; its strength also will increase. After carried out this experiment, we realized that our prediction is correct. Once the number of straw increases as the result the length of stretched straw will decrease due to the constant weigh. While, when the length of stretched straw decreases; the strength of straw will increase. This is mean; the number of straw used is proportional to the strength of straw when weigh is constant. Or, in equation form; a b, where: a = Number of straw used b = The strength of straw. According to the result, what we can say is there are some weaknesses in running the experiment. Obviously, this thing we can see in the second trial. More specifically for the 2 straws and 3 straws. There is just little difference between the lengths. This thing cant happen because logically when the number of straw increase as the result the length of straw should be drastically increase too. All these weaknesses occurred due to some reasons: 1. This thing might happen in virtue of our mistake while taking the readings from meter ruler. We should be careful because the parallax error and zero error might occur while taking the reading. 2. Besides that, the effects of a change in surroundings might also affect the result of this experiment. It might in the form of sunlight, wave, water moisture and so forth. 3. Apart from that, many laboratory apparatus that we used is in dissatisfied condition and already outdated. For example, we realized that the scale meter ruler is not accurate or precise than it supposed to be. 4. The observer being less than perfect in the same way every measurement. There are several ways to overcome these problems from occurred again. We can prevent it by making some improvements: 1. First and foremost, try to avoid mistake while taking the readings from the measurement device. We should realize that parallax and zero error can occur while taking the measurement of the length of stretched straw. 2. Besides that, in order to get an accurate result we should use the laboratory apparatus which in the best condition. 3. We also can repeat this experiment may be for 3 or 5 times in order to obtain an accurate result. This is because we can avoid random errors. 4. We also need to be more careful and cautious in running this experiment. Conclusion: 1. Hypothesis is valid and accepted. 2. After running this experiment, we realized that once the number of straw increases as the result the length of stretched straw will decrease due to the constant weigh. While, when the length of stretched straw decreases; the strength of straw will increase. This is mean; the number of straw used is proportional to the strength of straw when weigh is constant.