# Chapter2 metricscientificnotationaccuracy-110921113939-phpapp02

2 May 2018
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### Chapter2 metricscientificnotationaccuracy-110921113939-phpapp02

• 6. English vs. Metric Units Left Image: http://webapps.lsa.umich.edu/physics/demolab/controls/imagedemosm.aspx?picid=1167 Right Image: http://share.lancealan.com/N800%20ruler.jpg Which is longer? A. 1 mile or 1 kilometer B. 1 yard or 1 meter C. 1 inch or 1 centimeter 1.6 kilometers 1 mile 1 yard = 0.9444 meters 1 inch = 2.54 centimeters
• 7. Metric Units of Length The basic unit of length in the metric system in the meter and is represented by a lowercase m. Metric Units 1 Kilometer (km) = 1000 meters 1 Meter = 100 Centimeters (cm) 1 Meter = 1000 Millimeters (mm) Which is larger? A. 1 meter or 105 centimeters B. 4 kilometers or 4400 meters C. 12 centimeters or 102 millimeters D. 1200 millimeters or 1 meter
• 8. Measuring Length How many millimeters are in 1 centimeter? What is the length of the line in centimeters? _______cm What is the length of the line in millimeters? _______mm 1 centimeter = 10 millimeters What is the length of the line to the nearest centimeter? ________cm
• 9. English vs. Metric Units Which is larger? 1. 1 Pound or 100 Grams 2. 1 Kilogram or 1 Pound 3. 1 Ounce or 1000 Milligrams 1 pound = 453.6 grams 1 kilogram = 2.2 pounds 1 ounce of gold = 28,349.5 milligrams
• 10. Metric Units of mass Mass refers to the amount of matter in an object. The base unit of mass in the metric system in the kilogram and is represented by kg. Metric Units 1 Kilogram (km) = 1000 Grams (g) 1 Gram (g) = 1000 Milligrams (mg) Which is larger? A. 1 kilogram or 1500 grams B. 1200 milligrams or 1 gram C. 12 milligrams or 12 kilograms D. 4 kilograms or 4500 grams Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram
• 11. English vs. Metric Units Which is larger? A. 1 liter or 1 gallon B. 1 liter or 1 quart C. 1 milliliter or 1 fluid ounce 1 gallon = 3.79 liters It would take approximately 3 ¾ 1-liter bottles to equal a gallon. 1 fl oz = 29.573 ml 1 12-oz can of soda would equal approximately 355 ml. 1 quart = 0.946 liters
• 12. Metric Units Volume is the amount of space an object takes up. The base unit of volume in the metric system in the liter and is represented by L or l. Metric Units 1 liter (L) = 1000 milliliters (mL) 1 milliliter (mL) = 1 cm3 (or cc) = 1 gram* Which is larger? A. 1 liter or 1500 milliliters B. 200 milliliters or 1.2 liters C. 12 cm3 or 1.2 milliliters*
• 13. Measuring Volume We will be using graduated cylinders to find the volume of liquids and other objects. Read the measurement based on the bottom of the meniscus or curve. When using a real cylinder, make sure you are eye-level with the level of the water. What is the volume of water in the cylinder? _____mL What causes the meniscus? A concave meniscus occurs when the molecules of the liquid attract those of the container. The glass attracts the water on the sides.
• 14. Measuring Liquid Volume Imagescreatedathttp://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf What is the volume of water in each cylinder? Pay attention to the scales for each cylinder.
• 15. Measuring Solid Volume 10 cm 9 cm 8 cm We can measure the volume of regular object using the formula length x width x height. _____ X _____ X _____ = _____ http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/e n/syllabus/unit14/new/testingmain1.htm We can measure the volume of irregular object using water displacement. Amount of H2O with object = ______ About of H2O without object = ______ Difference = Volume = ______
• 16.  How hot? How cold?  direction of HeatTransfer  Celsius – 0 0C Freezing Point ofWater 100 0C Boiling Point ofWater  Kelvin = C° + 273  No degree signs are used  O Kelvin = -273.150 C ▪ coldest possible temperature
• 17.  Length – size  meter (m)  Mass – amount of matter  Kilogram (kg) or gram (g)  Volume – space something takes up  Liter (l) or centimeters cubed (cm3)  Temperature – amount of heat  Kelvin (K) = celsius + 273
• 18.  Measure of how much matter is squeezed into a given space  density = mass volume
• 19.  A block of wood and a block of steel have the same volume
• 20.  What happens to the density of an object if it is cut into pieces?  Which has the greater density, a single uranium atom or Earth?
• 21.  coefficient x 10 raised to a power  Single gram of hydrogen  602,000,000,000,000,000,000,000 molecules =  6.02 x 1023 molecules  Mass of an atom of gold  0.000000000000000000000327 grams =  3.27 x 10-22 grams
• 22.  36,000  3.6 x 104  503,000,000  5.03 x 108  0.00076  7.6 x 10-4
• 23. The valid digits of a number In measurement: includes all of the digits that are known, plus a last digit that is estimated
• 24.  Significant:  nonzero digits  final zeros after the decimal points  zeros between two other significant digits  Not significant  zeros used solely for spacing the decimal point are not significant.
• 25.  each have only two sig figs  0.0071 meter  0.42 meter  0.000099 meter  7.1 x 10-3 meter  4.2 x 10-1 meter  9.9 x 10-5 meter
• 27. If the digit immediately to the right of the last significant digit is less than 5, it is dropped  5 or greater - last significant digit increased by 1  41.58 square meters  41.6 square meters
• 28.  Round 65.145 meters to 4 sig figs  65.15m  Round 100.1°C to 1 sig fig  100°C  Round 154 cm to 2 sig figs  150  Round 0.000718 kilograms to 2 sig figs  0.00072
• 29.  Counting  Example: 23 people in the classroom ▪ (Not 22.9 or 23.1) 23.00000000……………….  Exactly defined quantities  Example: 60 minutes = 1 hour ▪ 60.00000000……………………..
• 30.  calculated answer cannot be too precise  not more precise than the least precise measurement  Multiplication and Division  same number of sig figs as the measurement with the least number of sig figs  Addition and Subtraction  same number of decimal places as the measurement with the least number of decimal places
• 31.  Accuracy  How close a measurement comes to the actual value of what is being measured  Precision  How close a series of measurements are to one another
• 32.  Difference between accepted value and experimental value  error = experimental value – accepted value  % error = x 100%error accepted value
• 33.  % error = x 100% 99.1°C – 100.0°C x 100% 100.0°C 0.9°C x 100% 100.0°C 0.9% error accepted value = = =