150 likes | 356 Views
Scientific Measurements. Scientific Measurements. Measurement : a means of describing observations using numbers and a UNIT of measure (ex: 11 inches ). - makes a comparison with a known standard.
E N D
Scientific Measurements Measurement: a means of describing observations using numbers and a UNIT of measure (ex: 11 inches) - makes a comparison with a known standard - ALL measurements contain at least one of the fourbasic dimensional quantities (length, mass, time, temperature) Systems of measurement: Metric System (aka International System of Units(SI)
Basic Measurement Units Unit Metric Instrument Time: instant something happens OR period of change Length: distance between 2 points Mass: amount of matter in an object Temperature: measurement of how hot or cold something is (average KE = average Kinetic Energy) Second (s), minute (min), hour (hr), year (yr)Meter (m), centimeter (cm), millimeter (mm), kilometer (km) Gram (g), kilogram (kg) Celsius (0C) Kelvin (0K) Clock, stopwatch, sundial, hour glass Meter stick, ruler, tape measure Balance, scale Thermometer
Derived Units ** Some properties are best described by using some mathematical combination of the basic quantities. These mathematical combination of basic quantities are referred to as DERIVED UNITS. Examples ofDerived Units: Volume; Density Volume: amount of space an object takes up Regular Shape: Volume L . W . Hcm . cm . cm = cm3 Irregular Shape: displacement method (1 ml = 1 cm3)Drop object in known volume of water and record the difference
Volume Practice: L x W x H 1. Find the volume of a block that is 5cm in length, 3cm in width, and 8 cm in height. 2. What would the volume be for the object below? 3. What would the volume be for the object below? 120cm3 60cm3 78in3
Let’s measure some irregular shapes! What is the volume of the dinosaur in ml? 0.8 ml
Volume of irregular objects practice 60 ml 3 ml
Working With Numbers Rounding off numbers: most of the time to the nearest 10th or 100th Every number has a decimal version (4 = 4.0) Rules: you always check the number to the rightto decide > 5 Ex: 5 . 362 8 <4 Leave it alone thousandths tenths hundredths (5.363) (5.4) (5.36) The “rules” Five or more, raise the score Four or less, leave it rest
Working With Numbers Rounding Practice Time • Round to the nearest tenths place: • 3.73= • 2. 65= • 4.324= • 18.957= • 2345.5867= • Round to the nearest Hundredths place: • 6.546= • 16.342= • 124.8573= • 12.997= • 2345.5867= 6.55 3.7 2.7 16.34 4.3 124.86 19.0 13.00 2345.6 2345.59
There are several metric unit prefixes. The ones we use in science are kilo-, hecto-, deka-, deci-, centi-, and milli. • Write the meaning and abbreviations for the following prefixes: • Kilo: • Hecto: • Deka: • Deci: • Centi: • Milli: k, 1000 h, 100 da, 10 d, 0.1 c, 0.01 m, 0.001
To remember the order of the prefixes in order from largest to smallest use the following sentence: King Henry Doesn't [Usually] Drink Chocolate Milk kilo- hecto- deka- [unit] deci- centi- milli- • Each step is ten times or one-tenth as much as the step on either side: • 1 kilometer = ____ hectometers = ______ dekameters = ________meters = _________ decimeters = ____________ centimeters = _______________ millimeters Alternatively • 1 milliliter = ____ centiliters = _______ deciliters = _________ liters = ____________ dekaliters= ______________ hectoliters = ______________ kiloliters 10 100 1000 10,000 100,000 1,000,000 10 100 10,000 1000 100,000 1,000,000
Right • The point here is that you move from one prefix to another by moving the decimal point one place, filling in, as necessary, with zeroes. To move to a smaller unit (a unit with a prefix some number of places further to the ____________ in the listing), you move the decimal place to the right that same number of places. • Convert 12.54 kilometers to centimeters. • How many jumps is it from "kilo-" to "centi-“?________, to the right. • Kilo- Hecto- Deka- [Meters] Deci- Centi- Milli • So I move the decimal point five places to the right, filling in the extra space with zeroes: 12.54 12.54km= ______ cm 5 0 0 0 1,254,000
Left • To move to a larger unit (a unit with a prefix some number of places further to the right in the listing), you move the decimal place to the __________ that same number of places. • Convert 457 ml to hl • How many jumps is it from “milli” to “hector”? ________, to the left. • Kilo- Hecto- Deka- [Meters] Deci- Centi- Milli • So I move the decimal point five places to the Left, filling in the extra space with zeroes: 457 14. 457ml= 5 . 0 0 0.00457 hl
Practice Kilo- Hecto- Deka- [Meters] Deci- Centi- Milli • 12mm =________dm • 2) 4km=______cm • 3) 5.678hm=______mm 0.12 400,000 567,800
Who wants more practice : Volume Rounding Unit Conversions Try,“Working With Numbers worksheet”