1. Lesson 5.2 Archimedes’ Principle
10/24/11
Lesson 5.2 Archimedes’ Principle
Catalyst
1. Calculate the density of a liquid with a mass of 90 g and a volume of 45 mL.
D = m/v 90g/45mL = 2 g/mL
2. How can you use the density of an object to predict whether it will float or sink?
If an object has a density less than or equal to 1 g/mL it will float. If its density is more than 1 g/mL, it will sink.
Period 3: Hand in your goal reflection at this time in the wire basket in the front of the room.
22L

2. Lesson 5.2 Archimedes’ Principle
10/24/11
Lesson 5.2 Archimedes’ Principle
Catalyst
Homework
Study for Unit 5 exam on Friday.
22L

3. Lesson 5.2 Archimedes’ Principle
10/24/11
Lesson 5.2 Archimedes’ Principle
Catalyst
Homework
Egg and Water Demo
1. Do you think there will be a difference in density between the fresh water and the salt water? Why or why not? Will the egg float or sink?
2. Was your prediction accurate? What actually happened?
22L

4. Lesson 5.2 Archimedes’ Principle
10/24/11
Lesson 5.2 Archimedes’ Principle
Archimedes’ Principle Video and Notes
Turn to p. 428.
22R

5. Finding the Density of Liquids—use your guided notes!
Remember… Density = mass/volume, so we need to find the MASS and VOLUME of the liquid to find its DENSITY.
1. Find MASS of EMPTY cylinder in g.
2. Fill cylinder with liquid. Record VOLUME in mL.
3. Find MASS of FILLED cylinder (liquid + cylinder) in g.
4. Find mass of LIQUID ONLY = FILLED cylinder’s mass – EMPTY cylinder’s mass
5. Divide mass of LIQUID ONLY by volume.

6. Example 1
This graduated cylinder has a mass of 25 g when empty. After being filled, its new mass is 111 g. What is the liquid’s density?
Mass of Cylinder and Liquid =_____
Mass of Empty Cylinder =_____
Mass of Just Liquid =_____
Volume = ___________
DENSITY = ___________

7. Example 2
This graduated cylinder has a mass of 50 g when empty. After being filled, its new mass is 103 g. What is the liquid’s density?
Mass of Cylinder and Liquid =_____
Mass of Empty Cylinder =_____
Mass of Just Liquid =_____
Volume = ___________
DENSITY = ___________

8. Example 3
This graduated cylinder has a mass of 15 g when empty. After being filled, its new mass is 195 g. What is the liquid’s density?
Mass of Cylinder and Liquid =_____
Mass of Empty Cylinder =_____
Mass of Just Liquid =_____
Volume = ___________
DENSITY = ___________

9. Example 4
This graduated cylinder has a mass of 10 g when empty. After being filled, its new mass is 30 g. What is the liquid’s density?
Mass of Cylinder and Liquid =_____
Mass of Empty Cylinder =_____
Mass of Just Liquid =_____
Volume = ___________
DENSITY = ___________

10. Example 5
What is the liquid’s density in g/mL?

11. Now it’s your turn to try it on your own!
Finish the Independent Practice problems on the back hand side of your worksheet.

12. Lesson 5.2 Archimedes’ Principle
10/24/11
Lesson 5.2 Archimedes’ Principle
Group Work
--Density Worksheet (10 min)
--Go over as a class (5 min)
--Other side (15 min)
Quiz: Put everything away except a separate sheet of paper and a pencil.
Number your paper # Multiple choice, just write the letter.
22L

13. Number your paper #1-15. Multiple choice, just write the letter.
10/24/11
Quiz: Put everything away except a separate sheet of paper and a pencil.
Number your paper # Multiple choice, just write the letter.

14. Lesson 5.3 Density and Buoyancy Practice Catalyst
10/26/11
What is the density of the liquid in the graduated cylinder below?
30.0 g
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15. Quiz Corrections: Put corrected by and your name at the bottom.
Follow along with the document reader.
Put the number correct over 15 at the top.
Put a 1, 2, 3, 4, or 5 as well. Refer to the board for the scale.
Return the quiz to the person it belongs to.
Put your own quiz in your folder—ON TOP!!!!!!!!
10/26/11

16. --Density Worksheet (10 min) --Go over as a class (5 min)
10/26/11
Lesson 5.3 Density and Buoyancy Practice
Group Work
--Density Worksheet (10 min)
--Go over as a class (5 min)
--Other side, Still dense about density? (15 min)
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17. Penny Boats Competition:
You will choose your groups of 4.
Each group will receive 1 piece of tin foil and 1 penny.
Your group must construct a boat that will be able to hold as much weight as possible.
Then, we will have a competition to see whose boat can hold the most weight.
10/26/11