1 / 16

160 likes | 473 Views

Chapter 2: Measurements and Calculations. Scientific Method. Logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data. Observing: the use of senses to obtain information

Download Presentation
## Chapter 2: Measurements and Calculations

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**Scientific Method**• Logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data. • Observing: the use of senses to obtain information • Qualitative vs. Quantitative • Examples? • System: Specific portion of matter in a given region of space that has been selected for study during an experiment or observation • Examples?**Hypothesis**• Testable statement • If-then statements • Ex. If sunlight stimulates plant growth, then plants placed in direct sunlight will grow faster than those placed in the shade. • Need data from an experiment to support or refute the hypothesis (NOT prove or disprove) • Control vs. Variable**Theorizing**• When data supports the hypothesis, scientists try to explain the phenomenon with a model • Model: an explanation of how phenomena occur and how data or events are located • Can be in picture/physical form but not always the case • Theory: broad generalization that explains a body of facts or phenomena • https://www.sciencenews.org/blog/context/top-10-revolutionary-scientific-theories**Plant Growth?**• Design a lab using the scientific method that will explore what makes plants grow. • Use the lab report from yesterday as a starting point/reference. • Explain which type of research this would fall into and give evidence to support your claim.**Measurements**• Quantity: something that has magnitude, size or amount • Quantity is not the same thing as a measurement • Ex. A teaspoon is a unit of measurement and volume is its quantity • Measurements require a unit • Measurements were not always standard • Ex. A foot was not always 12 inches**SI Measurements**• Le Systeme International d’Unites • Abbreviated to SI • Adopted in 1960 by the General Conference on Weights and Measures • SI base units • Meter, kilogram, second, kelvin, mole, ampere, candela • Prefixes (ex. Mega, kilo, hecta, deka, deci, centi, milli, micro, nano, pico)**Conversion Factors**• A ratio derived from the equality between two different units that can be used to convert from one unit to the other • Ex. Quarters in a dollar How many quarters are in 5.25 dollars? • Dimensional Analysis: math technique that allows you to use units to solve problems involving measurements • Solve the problem above using both conversion factors to demonstrate how you choose the correct conversion factor.**Tips and Tricks**• When there is not a number in the denominator, you assume 1. • When asking ”How do I begin the setup,” always start with what you know and identify where you want to go. This will help you pick the correct conversion factor. • ALWAYS DOUBLE CHECK YOUR UNITS . • Cancel out any units that appear both on the top and bottom of any conversion factors you use in a problem.**Accuracy VS Precision**• Accuracy: the closeness of measurements to the correct or accepted value of the quantity measured • Close to the desired value • Precision: closeness of a set of measurements of the same quantity made in the same way • Close to one another but not necessarily close to the desired value

More Related