Measurement Notes Chapter 2 Section 1 & 2

Precision Vs. Accuracy Precision- is a description of how close measurements are to each other. A clock with a second hand is more precise than a clock with only a minute or an hour hand. TrialsTime (s) Trial Trial Trial Trial Trial TrialsTime (s) Trial Trial Trial Trial Trial AB Which is more precise?

Precision Vs. Accuracy Accuracy- Comparing a measurement to a real, actual, or accepted value. A clock that is set ten minutes fast is not as accurate as one that is set at the actual time. TrialsAcceleration (m/s squared ) Trial Trial Trial Trial 49.9 Trial 59.0 The accepted value of the acceleration due to gravity is 9.8 m/s (squared) Which trial is the most accurate?

International System of Measurement In 1960 this became the accepted system for measurement. This is the metric system and is what is commonly used in science. QuantityUnitSymbol LengthMeterm Massgramg TemperaturekelvinK TimeSeconds Electric currentAmpereA Amount of substancemolemol Liquid VolumeLitersL Solid VolumeCubic meters m^3 WeightnewtonsN BASE UNITS

International System of Measurement Prefix Chart – Common Prefixes Kilograms: kg Milliliters: mL centimeters: cm PrefixMultiplier kilo-1,000 hecto-100 deka-10 [Unit]1 deci-0.1 centi-0.01 milli-0.001

Note Activity Time Mnemonic Device Definition: A mnemonic device is a sentence that helps us to memorize a string of words. For example, music students use "Every Good Boy Does Fine" to remember the order of notes on the treble clef. (E, G, B, D, F). Math students use "Please Excuse My Dear Aunt Sally" to remember the order of arithmetic operations (Parentheses, Exponent, Multiply, Divide, Add, Subtract.). But the range of usefulness extends beyond music and math. They are an invaluable resource whenever you are trying to remember something. Directions: Your assignment is to create a mnemonic device for the standard metric prefixes. You can be creative in the base unit area but all the other prefixes should be accounted for in the device. Remember, the purpose of this is come up with something that will always help you remember the correct order of metric prefixes so make it something creative or meaningful to you. SCHOOL APPROPRIATE Ex. King Henry Died Monday Drinking Chocolate Milk i e e e e e i l c k t c n l o t a e i t l o r i i Kilo Hecto Deka (Base: Meter, Liter, Gram) Deci Centi Milli

Units Length- is defined as the distance between two points Volume- the amount of space an object occupies Mass- the amount of matter in an object Weight- measurement of force. Weight depends on gravity and is measured in newtons (N). Temperature- physical property of how hot or cold something is. Rate- amount of change of one measurement in a give time. Example: (speed)

Data Vocabulary Observe- To use one or more of your senses (sight, sound, taste, touch, smell) to gain information Predict- Stating what you believe will happen in the future, or experiment