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Bell Ringer 10/1/10 - minutes

Bell Ringer 10/1/10 - minutes. An object has a mass of 30 kg and a volume of 5 liters. What is its density? An object has a volume of 11 mL and a mass of 419 g. What is its density?

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Bell Ringer 10/1/10 - minutes

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  1. Bell Ringer 10/1/10 - minutes • An object has a mass of 30 kg and a volume of 5 liters. What is its density? • An object has a volume of 11 mL and a mass of 419 g. What is its density? • A rock has a density of 20.0 g/cm3. What would the volume of 340 g of this rock be? Watch sig figs, units, & circle answers! • A rock has a density of 20.05 g/cm3. Jesse fills a graduated cylinder to a volume of 25.0 ml. He drops a sample of the rock into the g.c. and the water level rises to 29.5 ml. What is the mass of the sample? Show all work, round to the correct number of significant figures, and circle your answer. • Give 3 units for volume. • Give 3 units for mass. • Give 3 units for density. • A stack of nickels has a density of 8.6 g/cm3 and a volume of 7.5 cm3. What is the mass of the nickels? • A kiwi has a mass of 111.5 g and a density of 0.95 g/cm3. What’s it’s volume? • A 5.0 kg object has a volume of 3.0 liters. What’s its density? • An object with a density of 5.0 g/cm3 has a mass of 75.0 g. What is the object’s volume? • A block has dimensions 5.0 cm by 3.0 cm by 2.0 cm and a mass of 75.0 g. What is it’s density?

  2. Today you are going to… turn in syllabus look over all of our ocean questions do a couple practice problems complete the Earth as a System Reading Guide So you can… better appreciate the size/scale of Earth identify the parts of the Earth system & how they interact convert from km to mi You’ll know you’ve got it when you can answer the questions on the reading guide

  3. Bell Ringer 9/30/13 • 1 km = _____ m • What is volume? Units? • What is mass? Units? • What is density? Units? • W5SAYWoS

  4. Mass, Volume, and/or Density • Define mass in your own words. • Define volume in your own words. • Define density in your own words. • Fundamental or derived units? • What changes when you drink the pop out of a can? • What changes when you crush the can? • What changes when you cut an ice cube in half? • Compare a Styrofoam peanut and a grain of sand.

  5. Golf Ball in Graduated Cylinder

  6. Density! What is it?

  7. Pass Around Bottles • Hg & H2O

  8. Density • Density is the ratio of an object’s mass to its volume. • Density = mass/volume • Units of g/ml, kg/L, g/cm3, lb/gal, lb/ft3 • 1 g/cm3= 1000 kg/m3

  9. Density • A pure substance always has about the same density, no matter what size it is. (statue of liberty example)

  10. The composition was pure copper from 1793 to 1837. • From 1837 to 1857, the cent was made of bronze (95 percent copper, and five percent tin and zinc). • From 1857, the cent was 88 percent copper and 12 percent nickel, giving the coin a whitish appearance. • The cent was again bronze (95 percent copper, and five percent tin and zinc) from 1864 to 1962.(Note: In 1943, the coin's composition was changed to zinc-coated steel. This change was only for the year 1943 and was due to the critical use of copper for the war effort.) • In 1962, the cent's tin content, which was quite small, was removed. That made the metal composition of the cent 95 percent copper and 5 percent zinc. • The alloy remained 95 percent copper and 5 percent zinc until 1982, when the composition was changed to 97.5 percent zinc and 2.5 percent copper (copper-plated zinc). Cents of both compositions appeared in that year.

  11. A pure substance always has the same density! • The density is the same no matter how much or little of it you have.

  12. Bell Work 9/29 – 5 min • If you increased the mass of an object while keeping it’s volume constant, what would happen to it’s density? • If you increased the volume of an object while keeping it’s mass constant, what would happen to it’s density? • What does inverse mean?

  13. As you pass around these objects, put them in order of least to most dense. • A. shiniest block • B. other silver colored block • C. yellow block • D. golf ball • E. marble • F. mouse ball • G. gray cylinder of zinc

  14. Density, Floating, & Sinking • If it’s more dense than a liquid, it’ll __________ in it. • If it’s less dense than a liquid, it’ll __________ in it. • Orbits, ping pong ball, golf ball • Something with the same density as a liquid will ______. • Cannonball in mercury

  15. Sink n Float Stuff • Golf balls • Metal sphere ball in rocks changes!

  16. Review Anticipatory Set

  17. Now we’ll calculate the density of the objects! • For which objects did it seem extremely easy to compare the density? • To measure the volume of regularly shaped objects (cubes & rectangles) we measure the sides. • A. shiniest cube • B. other silver colored cube • C. yellow cube

  18. Bell Ringer 10/2/12 Put your homework upsidedown (facing me) on your desk. • 55.0 liters of a liquid has a mass of 41 kg. What is it’s density? Would it float in water? • A rock has a density of 20.0 g/cm3. What would the volume of 340 g of this rock be? • What is the volume of a 2 cm x 3 cm x 5 cm rectangle? • When you finish, work on the back of your density worksheet.

  19. Today you are going to… review density hw & finish the back So you can… solve density problems & complete tomorrow’s lab recognize how problems are graded You’ll know you’ve got it when you can answer the questions on the back of the worksheet

  20. 3. A 58.00 mL sample of mercury has a mass of 784.74 g. What is its density?

  21. 5. Pure gold has a density of 19.32 g/cm3. How large would a piece of gold be if it had a mass of 318.97 g?

  22. 6. A 200 cm3 sample of silver has a density of 10.5 g/cm3. What is it’s mass?

  23. Like # 12: Josh notes that 40.0 cm3 of a certain metal has a mass of 180.0 g. What would the mass of 295 cm3 be?

  24. The density of gold is 19.3 g/cm3. What would the volume of 1 oz of gold be? (1 oz = 28.3 g)

  25. Good tutors • Explain how and why, don’t just do the problem • Ask questions to help lead to understanding • Don’t give up! • Good learners • Ask questions when they don’t understand • Don’t give up!

  26. Calculating Density • First, you must be able to identify your variables. • 16.0 g • 25 g/mL • 0.56 kg/L • 85 cm3 • 250 L • 35 kg • 20 mL • 6.023 g/cm3 • 85 m3

  27. Bell Work 9/27 – 5 minutes • The sides of a rectangle measure 0.5 cm x 1.0 cm x 1.5 cm, and it has a mass of 2.25 g. What is it’s density? • Your trying to find the density of a 30.0 g irregularly shaped object. You put some water in a graduated cylinder and measure the water level to be 20.0 mL. You drop the object in, and the water level rises to 25.0 mL. What’s the object’s density?

  28. Density Triangle - Cover the letter of the variable you want to find and you will have the formula!  • For example, if you cover the "V", you will see the formula for volume is mass/density. • This can be done with any formula like this!

  29. 25 mL (milliliters) of liquid has a mass of 50 g (grams). What is the liquid’s density?

  30. 25 mL (milliliters) of liquid has a mass of 50 g (grams). What is the liquid’s density? D = M = 50 g = 2 g/ml V 25ml

  31. An object has a mass of 30 kg and a density of 5 g/mL. What is its volume?

  32. An object has a density of 10.0 g/mL and a mass of 419 g. What is its volume?

  33. Bell Ringer • A rock has a density of 20.05 g/cm3. Jesse fills a graduated cylinder to a volume of 25.0 ml. He drops a sample of the rock into the g.c. and the water level rises to 29.5 ml. What is the mass of the sample? Show all work, round to the correct number of significant figures, and circle your answer.

  34. Archimedes' principle • Archimedes' principle: When a body is fully or partly immersed in a liquid, that body experiences an upward force (the buoyant force) equal to the weight of the displaced liquid. The displaced liquid is that volume of liquid equal to the volume of the body below the water surface. • Density of Penny 3.11 grams [pre 1982] • 2.50 grams [post 1982] • Density of nail = 8.04 g/ml • Density of alcohol = 0.789 g/ml

  35. Bell Work 10/4 – 6 minutes(Include units & tell if each will sink or float) 1. A random solid has a mass of 24 g and a volume of 35 mL. What is its density? 2. An object has a mass of 18 kg and a volume of 3 liters. What is its density? 3. An object has a volume of 10.0 cm3and a mass of 73 g. What is its density? 4. If 60 mL of liquid has a density of 0.70 g/mL, what is its mass? 5. An object has a mass of 36 g and a density of 2.5 ml/g. What is its volume?

  36. Density Labs • Show all of your work for all 4 objects (16 pts) • Finding volume, equation, equation with substitution, answer with units • 4 points for behavior • Stay in own group • Only take one item at a time • Clean up

  37. Find density of cylinder • Show setup/procedure for finding density

  38. Density • Density of water (@ 4oC) = 1.000 g/ml = 1.000 kg/L • Gram was defined as “mass of 1 mL of water” • More dense than water  sinks • Less dense than water  floats • Same density  can be suspended anywhere in it something with the same density as water will level out in the middle. (show examples of each)

  39. Mass, Volume, Density? • 1. What changes when you drink the pop out of a can? • 2. What changes when you crush the can? • 3. Define mass in your own words. • 4. Define volume in your own words. • 5. What has more volume, a Styrofoam peanut or a marble?

  40. 25 mL (milliliters) of liquid has a mass of 50 g (grams). What is the liquid’s density?

  41. 25 mL (milliliters) of liquid has a mass of 50 g (grams). What is the liquid’s density? D = M = 50 g = 2 g/ml V 25ml

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