Measuring Volume & Density By: Brianna Shields September 14, 2005

DO NOW 1. Name the unit used to label mass 2. What is the first step for using a triple beam balance? 3. What tool is used to measure length?

Volume of a liquid Definition The amount of space a liquid takes up

Volume of a liquid Tool Graduated Cylinder

Volume of a liquid Units Milliliters (ml)

Volume of a liquid Formula Read the volume level from the bottom of the meniscus

Volume of an irregular solid Definition The amount of space a solid takes up

Volume of an irregular solid Tool Graduated cylinder

Volume of an irregular solid Units Milliliter (ml)

Volume of an irregular solid Formula Measure the difference in water levels

Volume of a cube Definition The amount of space a cube takes up

Volume of a cube Tool Metric Ruler

Volume of a cube Units Centimeters cubed (cm 3 )

Volume of a cube Formula Volume = length x width x height

Example What is the volume of the liquid at left?

Example What is the volume of the liquid at left?

What is the volume of the object ?

Example What is the volume of the cube at left?

Density Definition The number of particles that can be packed into a space

Density Tool Graduated cylinder or metric ruler AND triple beam balance

Density Units G.C. = g/ml Ruler = g/cm 3

Density Formula Density = mass divided by volume D =m/v

Density How to calculate density 1. Find the mass in g 2. Find the volume in ml or cm 3 3. Divide the mass by the volume 4. Round to the nearest tenth 5. Label answer with correct units

Density of Water Water’s Density 1.0 g/ml

Density Sink or Float? When d > 1.0 g/ml = sink When d< 1.0 g/ml = float

Density Estimating Density of sinking object is simply > 1.0 Density of floating object = % of object below water level

Density Cutting an object Density of a pure substance is always the same regardless of size

Example What is the density of the object to the left if m=79.4 g, v= 29.8 cm 3?

Example Which of the objects would sink? Float? Explain Densities of Common Elements and Compounds Water = 1.0 g/ml Methanol=.79 g/ml Gold g/ml Air=.0013 g/ml Iron= 7.8 g/ml Ice=.93 g/ml Mercury= 13.5 g/ml Aluminum= 2.7 g/ml Ethanol=.94 g/ml Oak= 0.85 g/ml

Example How would these materials layer in a container? Densities of Common Elements and Compounds Water = 1.0 g/ml Methanol=.79 g/ml Gold g/ml Air=.0013 g/ml Iron= 7.8 g/ml Ice=.93 g/ml Mercury= 13.5 g/ml Aluminum= 2.7 g/ml Ethanol=.94 g/ml Oak= 0.85 g/ml

Example Estimate the density of the material at the left

Example Estimate the density of the material at the left

Example Estimate the density of the material at the left

Example This block has a density of 10.0 g/cm 3. What is the density of the block at the left if it is cut in half?

Practice Work with your lab partner Complete the volume and density practice questions in your handout We will go over the correct answers next class

Hands On: Volume ObjectToolWorkAnswer 1. MarbleGraduated Cylinder

Hands On: Volume ObjectToolWorkAnswer 2. ToyGraduated Cylinder

Hands On: Volume ObjectToolWorkAnswer 3. Block 1RulerV = lxwxh

Hands On: Volume ObjectToolWorkAnswer 4. Block 2RulerV = lxwxh

Hands On: Volume ObjectToolWorkAnswer 5. Mystery Liquid Graduated cyclinder

Hands On: Density Object 1 Mass Volume

Hands On: Density Object 1 Density Answer Sink or Float

Hands On: Density Object 2 Mass Volume

Hands On: Density Object 2 Density Answer Sink or Float

Practice: Volume and Density 1a. What is the volume of liquid in the graduated cylinder on the right? 1a. V= 1b. If an object is placed into the same graduated cylinder and the water level rises up to 25 ml, what is the volume of the object? 1b. V=

Practice: Volume and Density 2. Calculate the volume of the cube 2. V= 3. The following measurements are taken of a wood block. Length =2.3cm, width = 6.0 cm, height = 4.2 cm. What is the cube’s volume? 3. V=

Practice: Volume and Density 4. Place the objects where they belong when placed into a container of water 4.

Practice: Volume and Density 5. If a bar of soap has a mass of 57.0 grams and a volume of 112 cm 3, what is its density? Label your answer. Will it sink or float in water? 5.