Properties of gases( pressure, volume, temperature by Boyle's Law) Research Paper

Properties of gases( pressure, volume, temperature by Boyle's Law) - Research Paper Example During the preliminary studies, Boyle systematically compressed air in a sealed glass tube with the mercury trapped in the side, (Stephen 146). He then varied the amount of mercury trapped in the tube and made observation on the pressure changes inside the column. He named the U-tube glass as manometer. Below is a diagram representing a simplified manometer. The setup shows a syringe with a completely sealed tip in a vertical position. The syringe is supported by a pre-drilled block as shown. The thin wire is used to let out the excess air trapped in the syringe when setting up the experiment. The wire is, however, removed just before the experiment begins. The block on top of the syringe serves as a shelf for the 1-kilogram bricks used to vary the pressure on the plunger. This experiment holds the finding by Robert Boyle that when the temperature of a gas is held constant; the pressure of the gas is inversely proportional to its volume. The relationship shows that when the volume increases, the pressure must decrease and vice versa is also

Research Methods Essay Example | Topics and Well Written Essays - 1000 words - 4

Research Methods - Essay Example According to Bryman (2008, p. 25), a sample has advantages than a complete count in that; Different sampling techniques exist and they are divided into two categories namely formal and informal (non probability sampling). The formal sampling techniques operate on a known probability of choosing and they include; simple random sampling, stratified sampling, cluster sampling, systematic sampling and multistage sampling. Simple random sampling is a technique where all the elements are said to have the same chance of being selected. The probability of selecting any elements in the population is equal (Green and Salkind 2008, p. 57). This technique is applied in cases where all the elements in that certain population have same traits (characteristics). Such populations are said to be homogenous. Another formal sampling technique is stratified sampling and is applied in cases where the population is made up of elements of different traits. In this technique, the population is sub-divided into non-overlapping sub-groups called strata (each is a stratum) each made up of elements with the same traits. Once this has been done, a simple random sample is selected from each stratum and then combined for final analysis. This technique is advantageous in that it eliminates biasness which is present if simple random sampling is used and also leads to higher precision. Cluster sampling on the other hand is a probability sampling technique in which the population is divided into clusters and then the researcher selects randomly the clusters to be included in the final analysis. It is mostly used in cases where getting the entire population for the research study is impossible or where the study population is concentrated in regions e.g. schools, churches, counties etc. The only disadvan tage of this technique is less precision than even simple random sampling and stratified sampling. Systematic sampling is the selecting of sample