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Density Physical Science 2012-2013 Bellringer Ms. Bisnow 9/13/12 Write the question and answer in your composition notebook. 1. A solar year is 365.24 days long. How many minutes are in one solar year? 2. A scientist recorded the volume of a liquid as 364.0 milliliters. Express this volume in deciliters. What is density? Density is a comparison of how much matter there is in a certain amount of space. Which one is more dense? Demonstration: People in a square How about this: Which square is more dense? Which one is more dense? Now which one is more dense? What is density? Density = mass OR volume mass ÷ volume. Units for density: g cm3 Why are these the units for density? ALWAYS .REMEMBER UNITS! Let’s try a density problem together Xavier has a paper clip. It has a mass of 9g and a volume of 3cm3. What is its density? Max also has an eraser. It has a mass of 3g, and a volume of 1cm3. What is its density? Work on these problems with your neighbor. Karen has a rock. The rock has a mass of 6g and a volume of 3cm3. What is the density of the rock? Anetria has a gel pen. The gel pen has a mass of 8g and a volume of 2cm3. What is the density of the rock? Now, try these on your own. David has a watch. It has a mass of 4g and a volume of 2cm3. What is the density of the watch? Jessica has a wallet. It has a mass of 15g and a volume of 5cm3. What is the density of the wallet? Predict which object has the most mass and which has the least. Paper clip Pencil Balloon Why does the wood float and the paper clip sink? The wood is heavier, but it is also less dense! SpongeBob floats, but Patrick sinks! Gizmo Instructions Go to www.explorelearning.com Click “enroll in a class” Your class enrollment code is __________. Username: Initials and student ID (AB306067) Password: Student ID (306067) Density Gizmo I will pick out different objects and stop to weigh the mass, and have students record in their notebooks the mass of each object. Together we will do the calculations and plan out in the notebooks how to properly set up these problems. Stations Station 1: Measure the volume of the block using rulers, and calculate the density. Each group will be required to measure 4 different blocks, switching once they are finished. Station2: Find the volume of each: a) rubber stopper and b) 5 pennies. Record it in mL. Compare the densities of diet and regular soda by placing each in a tank of water. Make a hypothesis on why your results occurred. 1. If the measurements of a metal bar are 10 cm, 5 cm and 2 cm, what is the volume of the metal bar? 2. John recorded the mass of a wooden block as 212 grams. Suppose the block was massed on the moon. Would you expect its mass to be the same? How about its weight? 3. If a book had a mass of 35 grams, and a volume of 40 cm3 would the book float in water? 4. 75 mL of water was measured. An object was carefully dropped into the graduated cylinder. The water level rose to 90 mL. What is the volume of the rock? 5. If the mass of an object is 30 grams and the volume of the 15 mL, what is the density?