Chapter 2.1 review Please bring dice on Wednesday, in a bag with your name inside. 7 steps of the scientific method Observation – notice with your senses, why are we interested in the topic? Hypothesis – prediction that can be tested by experimentation Experiment – procedure used to test a hypothesis, steps taken Results – experimental observations Data – information gathered during an experimtent Analysis -- Conclusions – what you learned fro the experiment. Was your hypothesis accepted or rejected? Repeat Report – to share your results with others. Lab report or presentation. Habits of a scientific mind:\ Imagination – ability to conceive of new ideas, creativity Curiosity – wonder about things, how things work Skepticism – do not believe everything you are told Openness to new ideas Control group – the group that does not receive the treatment Experimental group – the group that has the variable Variable – the factor of interest in an experiment Correlations – scientists use this to test predictions when it is impossible or unethical to test directly Ideas for experiment Coin flipping Rolling dice – craps, gambling, set up so house wins With 2 (6 sided) dice, what is the chance of rolling a 2,3,4,5,6,7,8,9,10,11,or 12 Observations – describe the dice, is there an equal chance of landing on any side? Hypothesis – pick a number between 1 and 13 and using logic, make a prediction about what percentage of the time you will get a sum of that number when you roll your two dice. How many ways can you role your sum. Experiment – design an experimental plan, write your plans in numbered steps. How will you record your results? Execute the experiment (do the experiment) Record your results and any relevant observations. Analysis – what does your data mean? Explain any calculations you make. Conclusions – What was the measured percentage that you actually came up with? Is this different than your hypothesis? Is it close to your hypothesis or not? Based on the results, do you accept or reject your hyothesis? Repeat – could anything be gained by repeating the experiment? Would you do anything differently? Are there any modifications or related experiments that you can think of that would be interesting? Report – write a lab report. This should contain 6 sections corresponding to each of the above parts of the scientific method. Each section should be in paragraph format with complete sentences. The one exception to this rule is the experimental section which can have the steps listed in order. |
Monday, September 8, 2008
2.1 review
metric
The Metric System The metric system is based on the number 10. There are, for example, 10 millimeters per centimeter. There are 1000 (10 times 10 times 10) meters per kilometer. (The prefix kilo- means one thousand times - so a kilometer is one thousand times the length of a meter.) There are one thousand milliliters in a liter. (The prefix milli- means "one thousandth of " - so one milliliter would be one one-thousandth of a liter.) In chemistry, physics - in fact, all the sciences, the metric system is used. The basic advantage to the metric system is that it is so easy to go from one unit to another. You just multiply or divide by 10. Basic unit for measuring length is the meter. The symbol is m. Basic unit for measuring volume is the liter. The symbol is v. Basic unit for measuring mass is the gram. The symbol is g. 1000 100 10 unit 1/10 1/100 1/1000 Kilo hecto deca deci centi milli k c m big medium small There are 1000 grams in a kilogram. 1,000g = 1 kg There are 1000 meters in a kilometer. 1,000m = 1km There are 1000 millimeters in a meter. 1,000mm = 1 m There are 1000 milliliters in liter. 1,000ml = 1 l Kilo- means 1000. The symbol is k. So the symbol for one kilogram is kg. Milli- means 1/1000 or one one-thousandth. The symbol is m. Centi- means 1/100th. The symbol is c. The symbol for centimeter is cm. There are 10 millimeters in one centimeter. 10mm = 1 cm 1kg = 1000g 1/1000kg = 1g 1g = 100cg = 1000mg Questions: 1. What is the symbol for millimeter? How many meters is this? 2. What is the symbol for kilogram? How many grams is this? 3. What is the symbol for a centiliter? How many liters is this? 4. How many millimeters in a meter? 5. How many millimeters in a centimeter? 6. How many centiliters in liter? 7. How many meters in a kilometer? 8. How many millimeters in a kilometer? 9. How many milliliters are there in one (1) liter? 10. Milli- means what? 11. Is a millimeter more or less than a meter? How do you know? By how much? 12. Is a kilogram more or less than a meter? How do you know? 13. If 200 milligrams is 200 one-thousandths of a gram, what would 900 milligrams be? 14. How many milligrams are in 1 gram? In two grams? In 5 grams? In 1000 grams? 15. How many milligrams in one kilogram? 16. 2,000mm = _______m 17. How many mm are there in one meter? 18. How many milliliters are there per liter? 19. How many milligrams are there per gram? 20. What do the following stand for? (a) milli-_____________ (b) centi-____________ (c) g _______________ (d) kilo-_____________ (e) mg______________ (f) cm_______________ (g) mm______________ For scale reference, just so you know: Your fingernail is about one millimeter thick and one centimeter wide. Your hand is about 10 centimeters wide or one decimeter. When you walk, one stride is almost one meter. It is also about a meter from your fingertips to you opposite shoulder. Most people drink about 2-3 liters per day. A liter of water weighs one kilogram. One milliliter of water weighs one gram. Our gram crackers weighed about 3.8 grams. Most of us weigh between 40 and 100 kilograms. A grain of rice could be measured in milligrams. |
1st lab report Rolling Dice Lab Assigned Thursday, 09-04-08, due Monday, 09-07-08 Rolling dice – craps, gambling, set up so house wins With 2 (6 sided) dice, what is the chance of rolling a 2,3,4,5,6,7,8,9,10,11,or 12? The goal of this lab is to answer this question. To simplify matters each student will only do the calculations for one of the above numbers (assigned by the instructor). 1. Observations Why were we interested in the topic? 10pts – describe the dice. What shape is it? How many sides? Do the sides look different? Is there an equal chance of landing on any side? You could discuss craps gambling and chance of winning here. 2. Hypothesis This should be a statement that can be tested by experimentation. 10pts – for your number between 1 and 13, using logic, make a prediction about what percentage of the time you will get a sum of that number when you roll your two dice. How many ways can you role your sum. Explain the logic you used to come up with your hypothesis. 3. Experiment: How was the experiment conducted? Procedure, steps of experiment. 40pts Results:Data and experimental observations: 10pts – Design an experimental plan, write your plans in numbered steps. Include how many times you will roll the dice. (This should be at least 50 times and no more than 200 unless you plan on finishing the lab at home.) How will you record your results? Design a table with 12 columns numbered 1-12. – Execute the experiment (do the experiment) Record your results and any relevant observations. 4. Analysis: This should include any charts or graphs of the data and interpretations of the graphs. 10pts – What does your data mean? What percentage of the time were you actually roll your number? Explain any calculations you make. 5. Conclusions: Was your hypothesis supported by the data or not? 10pts – What was the measured percentage that you actually came up with? Is this different than your hypothesis? Is it close to your hypothesis or not? Based on the results, do you accept or reject your hyothesis? 6. Repeat – could anything be gained by repeating the experiment? Would you do anything differently? Are there any modifications or related experiments that you can think of that would be interesting? 10pts 7. Report – write a lab report. This should contain 6 sections corresponding to each of the above parts of the scientific method. Each section should be in paragraph format with complete sentences. The one exception to this rule is the experimental section which can have the steps listed in order. |