Density Blocks and Cylinders Equal Mass and Equal Volume

Density Blocks In this activity, you will be dealing with nine cubes of different materials and five cylinders of various sizes and materials. Make all your measurements first, and save your calculations for later. In this way, everyone will get a chance to make the necessary measurements. Show all of your work, and be sure to include units! Printable copy of LAB

Cubes 1. Before doing any measurements, place the cubes in order by estimating the mass. The cubes should be labeled with a letter. If not, see the instructor. Using the letters from the cubes, write your order below: Smallest Mass ____ < ____ < ____ < ____ < ____ < ____ < ____ < ____ < ____ Largest Mass F A D C E I G B H

2. Using the triple beam balance, determine the mass of each cube (you should be able to measure to the nearest 0.1 g, or perhaps the nearest 0.05 g). Data Table 1: I H G F E D C B A Density (g/mL) Volume (cm 3 ) Mass (g) CubeDescription

Diameter vs. Radius vs. Circumference diameter radius v =  r 2 h

Cylinders v =  r 2 h 1. Before doing any measurements, place the cylinders in by estimating the mass. Smallest mass ________< ________ < ________ < ________ < _______ Largest mass C A B E D

1. Using the method of your choosing (two possible methods), determine the volume of each cylinder. Report your volume in cm 3 (remember that 1 cm 3 = 1 mL). If you decide to use the displacement method, please be sure to dry off the cylinders after determining the volume. Data Table 2: Sample Cylinder Color Length (cm) Initial Volume of Water (mL) Volume of Water & Sample Cylinder (mL) Float or Sink? Volume of Sample Cylinder (cm 3 ) Density (g/cm 3 ) A B C D E

Post-Lab Questions: Was the same amount of water displaced for each sample cylinder? Why? If all the sample cylinders were of equal volume, would the same amount of water be displaced for each sample? What was the relationship between the volume and density of sample cylinders? (Remember, they all have the same mass.) Did any of the sample cylinders float in water? If so, why?

Cubes 1. Before doing any measurements, place the cubes in order by estimating the mass. The cubes should be labeled with a letter. If not, see the instructor. Using the letters from the cubes, write your order below: Smallest Mass ____ < ____ < ____ < ____ < ____ < ____ < ____ < ____ < ____ Largest Mass F A D C E I G B H Least Dense I < H < A < B < G < C <D < F < E Most Dense

2. Using the triple beam balance, determine the mass of each cube (you should be able to measure to the nearest 0.1 g, or perhaps the nearest 0.05 g). Data Table 1: DescriptionCubeMass (g) Volume (cm 3 ) Density (g/cm 3 ) Opaque white plastic (nylon)A g16.4 cm g/cm 3 Clear plastic (lucite)B g16.4 cm g/cm 3 Gray solid metal (aluminum)C g16.4 cm g/cm 3 Rusty gray metal (steel)D g16.4 cm g/cm 3 Copper metal (Cu)E g16.4 cm g/cm 3 Brass metalF g16.4 cm g/cm 3 Dark gray plasticG g16.4 cm g/cm 3 Oak woodH g16.4 cm g/cm 3 Pine woodI 6.18 g16.4 cm g/cm 3

Cylinders v =  r 2 h 1. Before doing any measurements, place the cylinders in by estimating the mass. Smallest mass ________< ________ < ________ < ________ < _______ Largest mass 3. Place the cylinders in order from least dense to most dense. Least Dense B < A < C < D < E Most Dense 4. How were you able to determine this order? Calculating density from mass and volume data (or place in order of length...longest to shortest) ALL SAMPLES HAVE IDENTICAL MASS

1. Using the method of your choosing (two possible methods), determine the volume of each cylinder. Report your volume in cm 3 (remember that 1 cm 3 = 1 mL). If you decide to use the displacement method, please be sure to dry off the cylinders after determining the volume. Data Table 2: Sample Cylinder Color Length (cm) Initial Volume of Water (mL) Volume of Water & Sample Cylinder (mL) Float or Sink? Volume of Sample Cylinder (cm 3 ) Density (g/cm 3 ) A Off- white Sink B white Float C Dark gray Sink D Shiny gray Sink E brass Sink

Post-Lab Questions: Was the same amount of water displaced for each sample cylinder? Why? No, cylinders had different volumes. If all the sample cylinders were of equal volume, would the same amount of water be displaced for each sample? Yes, if they all had cylinders had the same volume they would displace the same volume of water. They would not have had the same mass. What was the relationship between the volume and density of sample cylinders? (Remember, they all have the same mass.) Smaller volume was most dense. Volume and density were INVERSELY related. Did any of the sample cylinders float in water? If so, why? Yes, cylinder B floated because it was less dense than water.

Teacher Notes This lab can easily be completed in one 50-minute class period. Do not allow students to determine the volume of the blocks using water displacement method. Several metals will oxidize (rust). Printable copy of additional LAB Printable copy of LAB Density of wooden blocks activity Printable copy of additional LAB Density homework problems worksheet