2 Density compares the mass of an object to its volume What is density?Density compares the mass of an object to its volume
3 Which one is more dense? Demonstration: People in a square How about this: Which square is more dense?How do you know?
4 Which one is more dense?Now which one is more dense?Why?
5 What is density? Density = mass OR. volume Units for density: g cm3 Why are these the units for density?ALWAYS REMEMBER UNITS!
6 a formula To find volume, use… water displacement 1. V = p r2 h V = l w h2.water displacementV = ?VfinalVinitVobject = Vfinal – Vinit
7 Equation of a Straight Line y = mx + bSlopeY intercept
8 Slope of a Straight Line The Slope of a straight line shows how steep a straight line is.Calculate: Divide the change in height by the change in horizontal distanceSlope = Change in YChange in X
9 Examples:Mass (g)Slope = 3 g = 1 g3mL mLdensityVolume (mL)Slope = density = 4 g = 2 g2mL mLMass (g)Volume (mL)
10 Solving problems in science using the GUESS strategy GivenUnknownEquationSubstituteSolve
11 Let’s try a density problem together Frank has a paper clip. It has a mass of 9g and a volume of 3cm3. What is its density?Frank also has an eraser. It has a density of 3g/cm3, and a volume of 2cm3. What is its mass?GUESm= 9 gV= 3 cm3DD= MVD = 9g3 cm33 gcm3GUESd= 3 g/cm3V= 2 cm3MD= MV3 = m26 g
12 Liquid Layers – Try with your neighbor Which liquid has the highest density?Which liquid has the lowest density?Which liquid has the middle density?
13 Liquid Layers Check out this picture. Which layer has the highest density? How do you know?Which layer has the lowest density?Imagine that the liquids on the right have the following densities:15g/cm g/cm33g/cm g/cm37g/cm g/cm3Match the colors to the correct densities.3g/cm37g/cm39g/cm310g/cm312g/cm315g/cm3