Ch 2 - Dimensional Analysis (Unit Conversion): 1st Quarter (Units 00-03): Silsby Science

Ch 2 - Dimensional Analysis (Unit Conversion)

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Mrs. Silsby's Step-By-Step Instructions on How to Convert Units:

Example: How many days are there in 950,400 seconds?

Conversion factors needed:

24 hours = 1 day 1 hour = 60 minutes 1 minute = 60 seconds

Step 1: Write down the order in which you'll need the conversion factors, starting with what you HAVE.

Have: 950,400 seconds

$seconds \rightarrow minutes \rightarrow hours \rightarrow days$

Step 2: Write down what you have and make it fraction by putting it over 1.

$(\frac{950,400 s}{1} )$

Step 3: Change your conversion factors into fraction form and place them so that the units will cancel diagonally.

$(\frac{950,400 s}{1} ) (\frac{1 min}{60 s}) (\frac{1 hr}{60 min})(\frac{1 day}{24 hrs})$

Step 4: Cancel UNITS (not their numbers)!!! You should be left with the units you were asked for in the numerator. (I would like to show the units actually crossed off, but still visible... Just imagine they are there...)

$(\frac{950,400}{1} ) (\frac{1}{60}) (\frac{1}{60})(\frac{1 day}{24})$

Step 5: Multiply everything on the top (the numerators).

$950,400 \times 1 \times 1 \times 1 day = 950,400 days$

Step 6: Multiply everything on the bottom (the denominator).

$1 \times 60 \times 60 \times 24 = 86,400$

Step 7: Divide the two numbers.

$\frac{950,400 days}{86,400} = 11 days$

Step 8: Determine the Significant Figures - and don't forget your units!

$Given\:950,400\:\sec\:-\:which\:has\:4\:Sig\:Figs.\:\:Answer=11.00\:days$

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[{section_type: "rich_text", content: "<h3>Mrs. Silsby's Step-By-Step Instructions on How to Convert Units:</h3>\nExample:  How many days are there in 950,400 seconds?\n \n Conversion factors needed:\n24 hours = 1 day                            1 hour = 60 minutes                         1 minute = 60 seconds\n \nStep 1: Write down the order in which you'll need the conversion factors, starting with what you HAVE.\nHave: 950,400 seconds\n<img class=\"equation_image\" title=\"seconds \\rightarrow minutes \\rightarrow hours \\rightarrow days\" src=\"https://lisd.instructure.com/equation_images/seconds%2520%255Crightarrow%2520minutes%2520%255Crightarrow%2520hours%2520%255Crightarrow%2520days\" alt=\"seconds \\rightarrow minutes \\rightarrow hours \\rightarrow days\">\n \nStep 2: Write down what you have and make it fraction by putting it over 1.\n<img class=\"equation_image\" title=\"(\\frac{950,400 s}{1} )\" src=\"/equation_images/%2528%255Cfrac%257B950%252C400%2520s%257D%257B1%257D%2520%2529\" alt=\"(\\frac{950,400 s}{1} )\">\n \nStep 3: Change your conversion factors into fraction form and place them so that the units will cancel diagonally.\n<img class=\"equation_image\" title=\"(\\frac{950,400 s}{1} ) (\\frac{1 min}{60 s}) (\\frac{1 hr}{60 min})(\\frac{1 day}{24 hrs})\" src=\"https://lisd.instructure.com/equation_images/%2528%255Cfrac%257B950%252C400%2520s%257D%257B1%257D%2520%2529%2520%2528%255Cfrac%257B1%2520min%257D%257B60%2520s%257D%2529%2520%2528%255Cfrac%257B1%2520hr%257D%257B60%2520min%257D%2529%2528%255Cfrac%257B1%2520day%257D%257B24%2520hrs%257D%2529\" alt=\"(\\frac{950,400 s}{1} ) (\\frac{1 min}{60 s}) (\\frac{1 hr}{60 min})(\\frac{1 day}{24 hrs})\">\n \nStep 4: Cancel UNITS (not their numbers)!!!  You should be left with the units you were asked for in the numerator. (I would like to show the units actually crossed off, but still visible... Just imagine they are there...)\n<img class=\"equation_image\" title=\"(\\frac{950,400}{1} ) (\\frac{1}{60}) (\\frac{1}{60})(\\frac{1 day}{24})\" src=\"https://lisd.instructure.com/equation_images/%2528%255Cfrac%257B950%252C400%257D%257B1%257D%2520%2529%2520%2528%255Cfrac%257B1%257D%257B60%257D%2529%2520%2528%255Cfrac%257B1%257D%257B60%257D%2529%2528%255Cfrac%257B1%2520day%257D%257B24%257D%2529\" alt=\"(\\frac{950,400}{1} ) (\\frac{1}{60}) (\\frac{1}{60})(\\frac{1 day}{24})\">\n \nStep 5: Multiply everything on the top (the numerators).\n<img class=\"equation_image\" title=\"950,400 \\times 1 \\times 1 \\times 1 day = 950,400 days\" src=\"https://lisd.instructure.com/equation_images/950%252C400%2520%255Ctimes%2520%25201%2520%255Ctimes%2520%25201%2520%255Ctimes%25201%2520day%2520%253D%2520%2520950%252C400%2520days\" alt=\"950,400 \\times 1 \\times 1 \\times 1 day = 950,400 days\">\n \nStep 6: Multiply everything on the bottom (the denominator).\n<img class=\"equation_image\" title=\"1 \\times 60 \\times 60 \\times 24 = 86,400\" src=\"https://lisd.instructure.com/equation_images/1%2520%255Ctimes%252060%2520%255Ctimes%252060%2520%255Ctimes%252024%2520%253D%252086%252C400\" alt=\"1 \\times 60 \\times 60 \\times 24 = 86,400\">\n \nStep 7: Divide the two numbers.\n<img class=\"equation_image\" title=\"\\frac{950,400 days}{86,400} = 11 days\" src=\"https://lisd.instructure.com/equation_images/%255Cfrac%257B950%252C400%2520days%257D%257B86%252C400%257D%2520%253D%252011%2520days\" alt=\"\\frac{950,400 days}{86,400} = 11 days\">\n \nStep 8: Determine the Significant Figures - and don't forget your units!\n<img class=\"equation_image\" title=\"Given\\:950,400\\:\\sec\\:-\\:which\\:has\\:4\\:Sig\\:Figs.\\:\\:Answer=11.00\\:days\" src=\"https://lisd.instructure.com/equation_images/Given%255C%253A950%252C400%255C%253A%255Csec%255C%253A-%255C%253Awhich%255C%253Ahas%255C%253A4%255C%253ASig%255C%253AFigs.%255C%253A%255C%253AAnswer%253D11.00%255C%253Adays\" alt=\"Given\\:950,400\\:\\sec\\:-\\:which\\:has\\:4\\:Sig\\:Figs.\\:\\:Answer=11.00\\:days\">"}]

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Ch 2 - Dimensional Analysis (Unit Conversion)

Mrs. Silsby's Step-By-Step Instructions on How to Convert Units:

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