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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” 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) 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 Which is larger? A. 1 liter or 1 gallon B. 1 liter or 1 quart C. 1 milliliter or 1 fluid ounce 1 gallon = 3.79 liters It would take approximately 3 ¾ 1-liter bottles to equal a gallon. 1 fl oz = 29.573 mL One 12-oz can of soda would equal approximately 355 mL 1 liter = 1.06 quarts •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… 1. 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! ) 2. 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” 3. Read the line where the meniscus touches as the volume of liquid being measured 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? •Between which two markings does the level fall? (Hint: Notice the interval markings) •What exact marking does the meniscus touch? 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 model triceratops?? 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) 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 this rectangular prism? l = 5 cm, w = 4 cm, h = 10 cm 5 cm x 4 cm x 10 cm 200 cm³ Technique 3: To find the volume of a Cylindrical Prism… Multiply ∏ r² h What is the volume of this cylindrical 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 Accelerated Bellwork: 6.6 mL 0.66 cL 0.066 dL 52.75 mL 0.0066 L 76 mL 5.275 cL 7.6 cL 0.5275 dL 0.76 dL 0.05275 L 0.076 L Find the volume shown by each of the following graduated cylinders: 9.75 mL • 35 mL • 6.1 mL