Lesson 061 Learning Goal You should be able
Lesson 061 Learning Goal: (You should be able to…) Describe density Calculate density Success Criteria: (Can you …) Define density Calculate density
How to organize lesson 060 The lessons Agenda was: W to T • Define density … notes • Calculate density … organizer
Vocabulary Terms 1. 2. 3. 4. 5. 6. 7. 8. Direct observation. Indirect observation. Inference. Seismic Waves Crust Mantle Outer Core Inner Core
Write to Think 061 Answer the following on lined paper… 1. Which do you think is usually more dense, a solid or a liquid? Explain… 2. What do you think is more dense, water or a rock? How could you test this? 3. Try to define density in your own words. 4. How does density connect to the Earth and Earth’s layers?
Plan of Action for today 1. 2. 3. 4. Density description/explanation Density modeling from your teacher. Density Practice with your partner. Calculate separately but work together.
Calculating Density Notes • Organize your binder with a lined piece of paper under lesson 061 • Main Title DENSITY • Make the subtitle mass vs. weight
Mass vs. Weight Mass: This Lego Millennium Falcon is made of a certain amount of ‘stuff’ (10, 179 pieces). That doesn’t change whether it’s on Earth, the moon, Jupiter or in space. Weight: Even though the number of pieces doesn’t change it weighs a different amount on different planets due to the force of gravity.
DENSITY: {the amount of ‘stuff’ (mass) in the space an object takes up} Not the same MASS of particles NUMBER of SIZE of particles in cube. Same Volume of cube Which cube do you think is more dense? Explain your thinking.
The Density Triangle V = m D = m V D m = D * V m D * V
Calculating Density Steps … and Organizer 1. Highlight the part of the equation in the triangle you’re trying to find 2. Circle the other parts of the equation in the triangle. 3. Write down equation in the appropriate format. 4. Re-write the equation by including the correct numbers in the correct place from the question. 5. Calculate the answer. USE A CALCULATOR! 6. Round your answer to correct number of places. 7. What are the correct units?
Calculating Density … example • Density can be calculated by dividing the mass of an object by its volume m D * V D = m V Sample Problem Timothy found a solid metal block that has a mass of 100 grams and a volume of 25 cm 3. What would be the density of the block? 4 grams D = 100 grams = 25 cm 3
Practice Problems 1. Find the density of a substance with a mass of 27 g and a volume of 7 cm 3. m D * V D = m V D = 27 g 3 7 cm = 3. 857 g cm 3 = 4 g cm 3 2. A block of maple has a mass of 20. 2 grams and a volume of 26. 5 cm 3. What is the density of the block? m D * V D = m V D = 20. 2 g 3 26. 5 cm = 0. 8 g cm 3
Question 1 Calculate the density of a material that has a mass of 52. 4 g and a volume of 13. 5 cm 3? 3. 88148 3. 9
End of Lesson
Direct vs Indirect observation • If you look at a cactus, you conclude: – this is a cactus and it has needles or spines. – You have observed the needles or spines. Direct. • You know that needles or spines are sharp. • If you look at a cactus, you conclude: – this is a cactus, it has needles or spines, it’s sharp. – You have observed sharpness/pain!. Indirect. • In case of direct observations you sense the phenomenon in question with your sensory organs directly. In indirect observations, you sense something intermediate that implies the phenomenon in question. • Intermediate obsevations can be many. The more intermediate things there are, the more careful you have to be with your conclusions.
Direct vs Indirect observation • Direct observations involve looking at the actual behavior or occurrence. • indirect observations involve looking at a result of that occurrence. • For example, if you were interested in seeing how much candy was given out by a particular neighborhood on Halloween, you could gather the information in one of the two following ways: • Direct observation: observe each house and count how many candies they give out. Indirect observation: look through trash cans the day after to see how many empty candy bags are in each trash bin. • Indirect observation tends to be used when the data cannot be gathered through direct means, or when gathering the data through direct observation tends to be too expensive or time consuming.
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