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Volume: Graduated Cylinder. What is volume? Volume – (def.) the amount of space an object takes up How could you find the volume of a glass of water? A penny? Glass of water – measure out the volume using a graduated cylinder Penny – use the “Water Displacement Method ”.
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Volume: Graduated Cylinder • What is volume? • Volume – (def.) the amount of space an object takes up • How could you find the • volume of a glass of • water? A penny? • Glass of water – measure out the volume using a graduated cylinder • Penny – use the “Water Displacement Method”
Tool: The Graduated Cylinder • Graduated cylinder (def) – A cylindrical tool used to measure the volume of liquids and irregular solids • Found in various sizes to hold different volumes of liquid • Measured in milliliters (mL)
What is a liter? cL kL mL L • Metric Benchmark: • The base unit used to measure volume in the metric system is the liter (L) • The volume of 1 liter was determined by calculating the size of one cubic decimeter • 10 cm x 10 cm x 10 cm = 1000 cm³ = 1L
Standard vs. Metric 1 fl oz = 29.573 mL One 12-oz can of soda would equal approximately 355 mL 1 liter = 1.06 quarts 1 gallon = 3.79 liters It would take approximately 3 ¾ 1-liter bottles to equal a gallon. Which is larger? A. 1 liter or 1 gallon B. 1 liter or 1 quart C. 1 milliliter or 1 fluid ounce
So How big is a Liter? • 1 milliliter (mL) = 1 cm3 (or cc) = 1 gram* • 5 milliliter (mL) = 1 teaspoon • 15 milliliter (mL) = 1 tablespoon • 240 milliliter (mL) = 1 cup • 1 liter (L) = 1000 milliliters (mL) • 3.8 liters (L) = 1 gallon
To find the volume of a liquid… • Pour the liquid into a graduated cylinder • (Be sure to use a measuring tool that is close in size to the object you are measuring! ) • Look at the water at eye level • If you look closely you will see that the surface of the water is not straight across, but curves slightly • This curve is called a “meniscus” • Read the line where the meniscus touches as the volume of liquid being measured
What is a meniscus? • The meniscus is (def.) the concave surface of a liquid used to determine volume in a graduated cylinder • To read the meniscus, look at the lowest point of the curve at eye level. *The meniscus forms when the molecules of the liquid become attracted to side of the container that holds them
Step 1:Find the two labels surrounding the water level. *The meniscus is between 50 mL and 60 mL Step 2:Use the labels to find the nearest graduated increment. Count up from the smaller line. *The meniscus is between 52 mL and 53 mL Step 3: Estimate the water level as accurately as possible based on the placement of the meniscus on the line. *The meniscus is about ¾ of the way between 52 mL and 53 mL, so the final reading would be 52.75 mL
Practice finding the volume for the next few graduated cylinders: • In between what two markings does the meniscus fall between? • What exact marking does the meniscus touch?
Practice Problems • Between which two markings does the level fall? • (Hint: Notice the interval markings) • What exact marking does the meniscus touch?
Measuring Irregular Solid Objects • Technique 1: To find the volume of an irregularly shaped object, you must use a method called the “Water Displacement Method” • How do I find the volume of this modeltriceratops??
The Water Displacement Method • Step 1 – Measure the volume of water in your graduated cylinder. Record your information. • Step 2 – Place the solid object into the cylinder. • Step 3 – Measure the new water level. • Step 4 – Subtract the old water level from the new water level. You now have the volume of the solid object. New Volume – Old Volume = Difference (Volume of object being measured)
Measuring Solid Objects • Technique 2: To find the volume of a Rectangular Prism… • Multiply the length (l) x width (w) x height (h) • What is the volume of thisrectangular prism? • l = 5 cm, w = 4 cm, h = 10 cm • 5 cm x 4 cm x 10 cm • 200 cm³ h w l
Measuring Solid Objects • Technique 3: To find the volume of a Cylindrical Prism… • Multiply ∏ r² h • What is the volume of thiscylindrical prism? • ∏ = 3.14 • r = 5 cm • h = 6 cm
Accelerated Bellwork: • Find the volume shown in each of the following graduated cylinders: • Write your units in mL, cL, dL and L A C B
Accelerated Bellwork: C A • 52.75 mL • 5.275 cL • 0.5275 dL • 0.05275 L • 6.6 mL • 0.66 cL • 0.066 dL • 0.0066 L B • 76 mL • 7.6 cL • 0.76 dL • 0.076 L
Science 8 Bellwork: • Find the volume shown by each of the following graduated cylinders: C A B
Science 8 Bellwork: A C B • 9.75 mL • 35 mL • 6.1 mL