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Conversions with Factor Label. Or How to change Faces into Turtles. Practice Sig Figs How many sig figs in:. 100 11010 11.010 0.000540 0.0004444 104,000 104,000. 1 4 5 3. 4 3 6. Factor Label Method. Line up the units so they cancel out Example problem
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Conversions with Factor Label Or How to change Faces into Turtles
Practice Sig FigsHow many sig figs in: 100 11010 11.010 0.000540 0.0004444 104,000 104,000. 1 4 5 3 4 3 6
Factor Label Method • Line up the units so they cancel out • Example problem • How many feet in 120 inches? • There are 12in in a foot • This can be written 12in or 1 foot 1 foot 12 in So the problem looks like 120 inches x 1 foot = 12 inches 120 ft = 10. ft 12
Conversions • Use conversion “factors” to trade from one type of unit to the other. • Just make sure the desired units are in the right place
Convert 300.9 grams to pounds • How many sig figs in data? 4 • How many sig figs in answer? 4 • What are units of answer? pounds • What are the units of the conversion factor? Grams x pounds = pounds grams • Put in numbers • 300.9 grams x 1 pounds = 0.6628 pounds 454 grams
Convert 1.02 lbs to grams454g = 1.000 lbs • How many sig figs in answer? • What are the units of the answer? • What are the units of the conversion factor? lbs x grams = grams lbs • Put in numbers 1.013 lbs x 454 grams = 459.9 grams 1.00 lbs
How About Other Practice • How many sig figs in answer? • What are the units of the answer? • What are the units of the conversion factor? • 12.509 Liters to gallons • There are 3.785 L in a gallon _______ x _______ = gallons
How many joules in 3.57 kilojoules? • How many megapascals in 3.78 x 104 centipascals? 3.57 x 103 3.78 x 10-4 Use agenda for conversion factors
Derived Units • More than one unit in a number • Density is a great example • Grams per milliliter • g/ml • Two units • How about lbs / gal to g / ml • 454g / lbs and 3875 ml / gal • Just do two conversions • Ready for another problem
How about lbs/gal to g/ml ? • 8.52 lbs / gal to g/ml 8.52lbs 1 gal X 454 g 1 lbs X 1 gal 3785 ml = 1.02 g ml
How about lbs/gal to g/ml ? • 8.52 lbs / gal to g/ml X g ? X 454 g 1 lbs 8.52lbs 1 gal X 1 gal 3785 ml X 1 ? ? = 1.02 g ml
Convert mpg to kpl100.0 miles to Km gallon liter • 100.0 mpg = ? Km per l • Data • 3.85 liters in a gallon • 1.61 km in a mile • Answer • Is …… 100.0 miles X 1.61 Km x 1 gallon = 41.8 km gallon 1 mile 3.85 liter liter
3.85 liters in a gallon 16 cups in a gallon2.54 cm in an inch 16 oz in a pound0.454kg in a pound 16 tablespoons in a cup3 teaspoons in a tablespoon • How many liters in 4.98 cups? • How many cm’s in 3.56 x 103 feet? • How grams in 2.05 pounds? • How many milliliters in 3.52 gallons? • How many teaspoons in 13 cups? • How many Tons in 1.53 x 106 oz.? • How many Kilograms in 1.53 x 106 oz?