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A pound of feathers or a pound of lead. Which has more weight? Which has more mass? Which has more volume? Which is more dense? . Density. For 2 items, both the same size, but having different masses, the one with the most mass will be more dense.
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A pound of feathers or a pound of lead • Which has more weight? • Which has more mass? • Which has more volume? • Which is more dense?
Density • For 2 items, both the same size, but having different masses, the one with the most mass will be more dense. • For 2 items of the same mass, but having different volumes, the one with the most volume will be the least dense.
m D x V Density….. ….is the amount of mass per volume. ….is measured in g/ml, g/cm³, kg/m³. …. is found using the formula D = m/v.
Volume • Measured in cm³, ml, L • For rectangular objects, volume is found from length x width x height • For cube shaped objects, volume is found from s³ • For irregular shaped objects, volume is found from the rise in water level when the object is dropped into a graduated cylinder containing water. • For a solid cylinder, volume is found using πr²h or by using the graduated cylinder method
Mass • Measured in g, kg, mg • The amount of matter in an object
1. What is the density of an unknown metal that has a mass of 158 grams and a volume of 20.0 ml? • Givens: Basic Formula:
What is the density of an unknown metal that has a mass of 158 grams and a volume of 20.0 ml? • Givens: M = 158 g V = 20.0 ml D = ? M V Basic Formula: D =
What is the density of an unknown metal that has a mass of 158 grams and a volume of 20 ml? • Givens: M = 158 g V = 20.0 ml D = ? M V Basic Formula: D = 158 g 20.0 ml D = =
What is the density of an unknown metal that has a mass of 158 grams and a volume of 20 ml? • Givens: M = 158 g V = 20.0 ml D = ? M V Basic Formula: D = 158 g 20.0 ml D = = 7.90 g/ml
2. What is the density of a block of wood whose dimensions are 4.0 cm x 10.0 cm x 6.0 cm and has a mass of 1200 grams? • Givens: Basic Equation:
What is the density of a block of wood whose dimensions are 4.0 cm x 10.0 cm x 6.0 cm and has a mass of 1200 gram? Givens: In this problem mass is given along with the dimensions of the block of wood. You must calculate the volume using 4 x 10 x 6 = 240 cm³.
What is the density of a block of wood whose dimensions are 4.0 cm x 10.0 cm x 6.0 cm and has a mass of 1200 gram? • Givens: Basic Equation: D = M = 1200 g V = 240 cm³ D = ? M V
What is the density of a block of wood whose dimensions are 4.0 cm x 10.0 cm x 6.0 cm and has a mass of 1200 grams? • Givens: Basic Equation: D = M = 1200 g V = 240 cm³ D = ? M V 1200 g 240cm³ D = = 5.0 g/cm³
3. What is the mass of a metal cube whose volume is 6.0 cm³and has a density of 5.0 g/cm³. • Givens: Basic Formula: Rearranged Formula:
M V • What is the mass of a metal cube whose volume is 6.0 cm³and has a density of 5.0 g/cm³. • Givens: Basic Formula: D = Rearranged Formula: M = d x V • D = 5.0 g/cm³ • V = 6.0 cm³ • M = ?
M V • What is the mass of a metal cube whose volume is 6.0 cm³and has a density of 5.0 g/cm³. • Givens: Basic Formula: D = Rearranged Formula: M = d x V • M = 5.0 g/ cm³ x 6.0 cm³ = 30 g = 3.0 x 101 g • D = 5.0 g/cm³ • V = 6.0 cm³ • M = ?
To find volume, when mass and density are given use the rearranged formula, V = What is the volume of a cube that has a mass of 45 grams and a density of 12 g/cm³? Givens: Basic formula: Rearranged formula: M D
5. What is the volume of a cube that has a mass of 45 grams and a density of 12 g/cm³? Givens: Basic formula: Rearranged formula:
M V What is the volume of cube that has a mass of 45 grams and a density of 12 g/cm³? Givens: Basic formula: D = m = 45 g Rearranged formula: V = D = 12 g/cm³ V = ? M D
M V What is the volume of cube that has a mass of 45 grams and a density of 12 g/cm³? Givens: Basic formula: D= m = 45 g Rearranged formula: V = D = 12 g/cm³ V = ? V = = M D 45 g 12 g/cm³
M V What is the volume of a cube that has a mass of 45 grams and a density of 12g/cm³? Givens: Basic formula: D= m = 45 g Rearranged formula: V = D = 12 g/cm³ V = ? V = = 3.75 cm³ = 3.8 cm³ M D 45 g 12 g/cm³
What is the density of a 32 gram irregular shaped rock if it raises the water level of a graduated cylinder from 45.0 ml to 54.0 ml? • Givens: Basic Formula:
6. What is the density of a 32 gram irregular shaped rock if it raises the water level of a graduated cylinder from 45.0 ml to 54.0 ml? • Givens: Basic Formula: D = m = 32 g v = 9.0 ml D = ? M V
What is the density of a 32 gram irregular shaped rock if it raises the water level of a graduated cylinder from 45.0 ml to 54.0 ml? • Givens: Basic Formula: D = m = 32 g v = 9.0 ml D = ? D = = M V 32g 9 ml
What is the density of a 32 gram irregular shaped rock if it raises the water level of a graduated cylinder from 45.0 ml to 54.0 ml? • Givens: Basic Formula: D = m = 32 g v = 9.0 ml D = ? D = = 3.555g/ml =3.6 g/ml M V 32g 9.0 ml
1 ml = 1cm³ • 1.0 ml of water has a mass of 1.0 gram so its density is 1.0 g/ml
Physical Science Homework • Work problems 1-3 on page 48.
Chemistry Homework • Page 32 – Problems 26- 28