Notes Science Essential Question(s) What is density? What is mass? What is volume? How do I calculate density? How do I multiply and divide with decimals? Tennessee SPI Objective: Apply an equation to determine the density of an object based on its mass and volume Check for Understanding Calculate the density of various objects. SPI Density

SPI Density What is density?  Density is the amount of matter (mass) you have crammed in a given space (volume) Reminder: mass is how much matter is in an object  The unit for mass is grams (mg or g or kg) Reminder: volume is how much space it takes up (size)  Unit for solid volume is cubic meters (cm 3 or m 3 or km 3 )  Unit for liquid volume is liters (mL or L or kL) To compute density  - divide the mass by the volume of the object Science Notes Demonstration: Demonstrate with wadded up paper in a trash can

Density Example:  Here are two objects that are the same size. (1) Bowling Ball and (2) Soccer Ball  One of these objects contains more matter (bowling ball).  With two same-sized objects like this, the object with more mass has greater density than the other object. More Dense Less Dense SPI Density Science Notes

 Soon you will get your first driver’s permit.  The place where you receive your driver’s permit is called the DMV (Department of Motor Vehicles)  Think of DMV for density SPI Density Science Notes Density Formula Use this formula: Density = mass divided by volume or Memory Trick D= M V Density = volume mass MVMV D = D= M V

Quick Practice SPI Density Science Solve the Density Problem Shown Below Go ahead and use a calculator (for now) 1) Calculate the density of an object with a mass of 25g and a volume of 10cm 3 Example: 25 (mass) divided by 10 (volume) Density= Units… g/cm 3 Answer 25g ÷ 10cm 3 = 2.5 g/cm 3 Don't Forget Your Units! Example: grams/centimeter cubed Written like this… g/cm 3

Quick Practice SPI Density Science Solve the Density Problem Shown Below Go ahead and use a calculator (for now) Don't Forget Your Units! Example: grams/centimeter cubed Written like this… g/cm 3 2) Calculate the density of an object with a mass of 45kg and a volume of 43m 3 Example: 45 (mass) divided by 43 (volume) Density= Units… kg/cm 3

Use this formula: Density=mass divided by volume Quick Practice SPI Density Science Solve The Three Density Problems Shown Below Go ahead and use a calculator (for now) Density= volume mass 2) Calculate the density of an object with a mass of 45kg and a volume of 43m 3 Example: 45 (mass) divided by 43 (volume) Density= D= M /V or MVMV D= Units… kg/cm 3 (round up to the nearest hundredth) 45kg ÷ 43m 3 = 1.05kg/m 3

Use this formula: Density=mass divided by volume Quick Practice SPI Density Science Solve The Three Density Problems Shown Below Go ahead and use a calculator (for now) Density= volume mass 1) …density of an object with a mass of 25g a volume of 10cm 3 ? Example: 25 (mass) divided by 10 (volume) 2) …density of an object with a mass of 45kg a volume of 43m 3 ? Example: 45 (mass) divided by 43 (volume) 3) …density of an object with a mass of 350g a volume of 95cm 3 ? Example: 350 (mass) divided by 95 (volume) Density= Density= Density= D= M /V or MVMV D= Units… g/cm 3 Units… kg/cm 3 Units… g/cm 3

Answers 1) …density of an object with a mass of 25g & volume of 10cm 3 ? 25g ÷ 10cm 3 = 2.5g/cm 3 3) …density of an object with a mass of 350g & volume of 95cm 3 ? (round up to the nearest hundredth) 350g ÷ 95cm 3 = 3.68g/cm 3 SPI Density Science Notes Density=mass divided by volume Don't Forget Your Units! Example: grams/centimeter cubed Written like this… g/cm 3

1) Identify which liquids would occupy levels A, B, and C according to their density. Level C Level B Level A DesignationSubstanceDensity Liquid 01Water1.0 g/mL Liquid 02Liquid Mercury13.6 g/mL Liquid 03Turpentine0.8 g/mL Turpentine (0.8 g/mL) Water (1.0 g/mL) Mercury (13.6 g/mL) SPI (Density) ANSWERS Science Notes SPI Density Density In Liquids Lower density liquids will float on top of liquids with higher density Example: Oil floats on top of water

SPI Density Science Notes Density In Liquids  Lower density liquids float on top of liquids with higher density  Higher density liquids will sink below lower density liquids View this YouTube Video Clip: Link: 7-Layer Density Column7-Layer Density Column

Mass: 12g Volume: 3cm 3 Mass: 23g Volume: 5cm 3 Mass: 11g Volume: 3cm 3 Mass: 19g Volume: 7cm 3 (A) (D) (C) (B) 4 g/cm g/cm g/cm g/cm 3 Science Notes SPI Density Which cube below has the GREATEST density? Again…go ahead and use a calculator (for now)