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Density . What is density ?. Density compares the mass of an object to its volume. Which one is more dense?. Demonstration: People in a square How about this: Which square is more dense? How do you know?. Which one is more dense?. Now which one is more dense? Why? . What is density?.
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What is density? • Density compares the mass of an object to its volume
Which one is more dense? • Demonstration: People in a square • How about this: Which square is more dense? • How do you know?
Which one is more dense? • Now which one is more dense? • Why?
What is density? • Density = mass OR. volume • Units for density: g cm3 • Why are these the units for density? ALWAYS REMEMBER UNITS!
V = ? To find volume, use… a formula 1. V = p r2 h V = l w h water displacement 2. Vfinal Vinit Vobject = Vfinal – Vinit
Equation of a Straight Line y = mx + b Slope Y intercept
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 distance Slope = Change in Y Change in X
Examples: density Mass (g) Slope = 3 g = 1 g 3mL mL Volume (mL) Slope = density = 4 g = 2 g 2mL mL Mass (g) Volume (mL)
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? m= 9 g V= 3 cm3 D D= M V D = 9g 3 cm3 3 g cm3 d= 3 g/cm3 V= 2 cm3 M D= M V 3 = m 2 6 g
Liquid Layers – Try with your neighbor • Which liquid has the highest density? • Which liquid has the lowest density? • Which liquid has the middle density?
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/cm3 10g/cm3 • 3g/cm3 9g/cm3 • 7g/cm3 12g/cm3 • Match the colors to the correct densities. 3g/cm3 7g/cm3 9g/cm3 10g/cm3 12g/cm3 15g/cm3