Measurement

TWO SYSTEMS METRIC  Used in science class and around the world  Can multiply by 10, 100, 1000, etc… to go from one unit to another  Common base units:  Meters for distance  Liters for liquid  Grams for mass  Newtons for weight  Celsius for temperature STANDARD  Used in America  Has uneven conversion factors (probably need to use a chart)  Common units:  Feet, inches, yards for distance  Ounces, cups, pints, gallons for liquid  Pounds for weight  Fahrenheit for temperature Common prefixes we will see in metric system: Centi- Hecto- Milli- Nano- Kilo-

CONVERSIONS WE SHOULD KNOW:  To go from milli- to another unit:  From milli- to centi- divide by 10  From milli- to a base unit (grams, liters, etc…) divide by 1000  To go from centi- to another unit:  From centi - to milli- mutiply by 10  From centi-to base unit (grams, liters, etc…) divide by 100  To go from kilo- to another unit:  From kilo to base unit (grams, liters, etc…) multiple by 1000  From a base unit (grams, liters, etc…) to centi-, milli-, or kilo-:  From base unit to milli-, multiply by 1000  From base unit to centi -, multiply by 100  From base unit to kilo-, divide by 1000

LENGTH  Distance from Point A to Point B  Can be used to find volume of a square or rectangle  Find the length, width, and height of the object  Multiply them together (L x W x H)- they can be interchangeable  Make sure your units are correct (cubed)  For example:  4 cm x 7 cm x 5cm =140 cm 3

Volume  Boxes and rectangles as described on the previous slide  Irregular objects (round, bumpy, triangular, etc…)  Water displacement method:  Fill graduated cylinder with a volume of liquid (lets say 30 ml)  Drop a ring into graduated cylinder and observe how far the water rose (lets say 70 ml)  Subtract the starting volume (30 ml) from the ending volume (70 ml) and it will tell you the object’s volume. In this case 40 ml.  Because it’s a solid, you need units to represent that.  1 ml= 1 cm 3, so if I have 40 ml this is 40 cm 3  Remember you need to read the meniscus (or curved line of water) for an accurate reading To read the meniscus, you want to be eye level to the container and take the reading at the bottom of the curve

Weight  Measure of how much gravity acts on an object  We use pounds everyday, however in science we use Newtons  This will change based on where you go in the universe  Because each planet or planetary body has it’s own gravitational force  So if you go somewhere with more gravity, you will weigh more  If you go somewhere with less gravity, you will weigh less  Use a scale to measure

MASS  Measure of how much stuff is in an object  We use grams  This will not change based on where you go in the universe  Because unless you lose part of yourself your mass will not change  So if you go somewhere with more gravity, you will have the same mass  If you go somewhere with less gravity, you will have the same mass  Use a balance to measure FUN FACT: On Earth, mass and weight are used interchangeably in everyday life

ACCURACY and PRECISION  Accuracy:  How close you are to the actual measurement  So if a book has a length of 15 centimeters, it is how many times you ARE CLOSE TO 15 cm.  Precision:  How many times you receive same result in your data  How many times you get the same result with a piece of equipment.  So if you receive 15 cm, 5 times, you have some precision to your measurement