# Physical Science Density & Buoyancy

Section 2: Physics: Lecture 4 | 23:43 min

Lecture Description

In this lesson our instructor talks about density and buoyancy. First, she discusses density and how to find density of an irregular object. Then she talks about buoyant force and floating vs. sinking. Four complete example videos round up this lesson.

Summer Ebs

Density & Buoyancy

Slide Duration:Table of Contents

Section 1: Chemistry

Properties of Matter

30m 50s

- Intro0:00
- Matter0:07
- Matter0:08
- Substance, Element, and Compound0:47
- Homogeneous and Heterogeneous Mixture1:47
- Suspension, Colloid, and Solution3:16
- Physical Properties5:25
- Appearance: Color, Shape, Size, Density, and State of Matter5:26
- Behavior: Viscosity, Magnetism, Malleability, and Ductility8:00
- Physical Changes10:29
- Physical Changes10:30
- Chemical Properties14:38
- Chemical Properties14:39
- Chemical Changes16:35
- Chemical Changes16:36
- Signs of Chemical Change16:55
- Example 1: Identify the Mixtures Listed19:21
- Example 2: Physical or Chemical Change?23:38
- Example 3: How Can You Separate a Mixture of Sand, Gravel, Iron, Filings, Salt, and Water?25:04
- Example 4: Physical/Chemical Property and Change27:27

Energy

53m 22s

- Intro0:00
- Energy0:03
- Energy Overview0:04
- Potential Energy1:48
- Potential Energy1:49
- Mechanical (Elastic) Potential Energy1:54
- Chemical Potential Energy3:15
- Nuclear Energy4:06
- Gravitational Potential Energy4:43
- Kinetic Energy7:34
- Kinetic Energy7:35
- Thermal Energy8:03
- Radiant Energy8:57
- Electrical Energy9:47
- Sound10:17
- Motion10:54
- Kinetic Energy: Example11:31
- Law of Conservation of Energy12:47
- Law of Conservation of Energy12:48
- Electrical to Radiant13:21
- Chemical to Thermal14:34
- Potential to Kinetic15:10
- Friction18:48
- Energy Resources20:06
- Nonrenewable: Fossil Fuels20:51
- Nonrenewable: Nuclear21:56
- Renewable: Solar26:50
- Renewable: Wind29:22
- Renewable: Tidal31:10
- Renewable: Hydroelectric32:30
- Renewable: Geothermal35:24
- Example 1: Gravitational Potential Energy38:40
- Example 2: Kinetic Energy42:20
- Example 3: Maximum and Minimum Potential and Kinetic Energy44:48
- Example 4: Should We Use Renewable or Nonrenewable Resources to Generate Electricity?46:31

Heat and States of Matter

48m 48s

- Intro0:00
- Temperature0:04
- Temperature0:05
- Fahrenheit to Celsius2:15
- Celsius to Fahrenheit4:29
- Kelvins to Celsius and Celsius to Kelvins5:50
- Thermal Energy8:06
- Thermal Energy, Kinetic Energy, and Potential Energy8:07
- Changing Thermal Energy: Temperature9:11
- Changing Thermal Energy: State of Matter9:37
- Changing Thermal Energy: Amount of Matter10:12
- Heat10:59
- Heat11:00
- Specific Heat12:21
- Transfer of Thermal Energy15:15
- Conduction15:16
- Convection16:43
- Radiation19:57
- States of Matter20:43
- Solids: Arrangement of Atoms, Shape, Volume, and Molecular Motion21:35
- Liquids: Arrangement of Atoms, Shape, Volume, and Molecular Motion23:49
- Gases: Arrangement of Atoms, Shape, Volume, and Molecular Motion25:33
- Plasma: Arrangement of Atoms, Shape, Volume, and Molecular Motion27:02
- Changing States of Matter27:49
- Melting27:50
- Freezing28:15
- Vaporization29:04
- Boiling29:17
- Condensation31:21
- Temperature and Time Graph32:18
- Thermal Expansion36:19
- Thermal Expansion of Solids37:16
- Thermal Expansion of Liquids38:17
- Thermal Expansion of Gases39:46
- Example 1: Converting Temperatures40:28
- Example 2: Thermal Energy43:35
- Example 3: Quick Matching44:58
- Example 4: Why Does It Feel Cold When You Put Your Hand On the Table?45:50
- Example 5: Heat Transfer46:48
- Example 6: Changing States of Matter47:29

Atoms and Elements

30m 12s

- Intro0:00
- Atoms0:05
- Atoms0:06
- Atomic Structure1:01
- Electron Cloud1:02
- Nucleus, Protons, and Neutrons1:43
- Quarks2:07
- Protons, Neutrons, Electrons2:40
- Protons, Neutrons, Electrons: Location2:42
- Protons, Neutrons, Electrons: Electric Charge3:05
- Examples4:10
- Electron Configuration5:32
- Electron Configuration5:33
- Elements12:22
- Atomic Number13:05
- Carbon13:15
- Oxygen14:49
- Important Elements for Living Things16:25
- Isotopes17:04
- Isotopes17:05
- Example 1: Atomic Structure and Electrical Charge21:16
- Example 2: Electron Configuration23:13
- Example 3: Electron Configuration24:57
- Example 4: Use the Periodic Table to Complete the Table Below26:08

Periodic Table

47m 23s

- Intro0:00
- Periodic Table0:06
- Atomic Number, Chemical Symbol, and Atomic Mass0:07
- Groups and Periods4:14
- Groups and Periods4:15
- Electron Dot Diagrams10:05
- Electron Dot Diagrams10:06
- Ion Formation19:09
- An Ion Forms When an Atom Gains or Loses Electrons19:10
- A Positive Ion Forms When an Atom Loses and Electron20:25
- A Negative Ion Forms When an Atom Gains an Electron26:49
- Oxidation Numbers28:51
- Oxidation Numbers28:52
- Metals, Nonmetals, Metalloids34:52
- Metals, Nonmetals, Metalloids34:53
- Example 1: Group and Period37:39
- Example 2: Electron Dot Diagrams39:50
- Example 3: How do Fluorine and Calcium Become Ions?42:10
- Example 4: What Are 2 Ways to Find the Oxidation Number of Sodium?44:58

Chemical Bonding, Part I

51m 6s

- Intro0:00
- Chemical Bonds Form Compounds0:17
- Atoms and Electrons0:18
- H2O2:14
- HCl3:36
- C6H12O64:16
- Ca(NO3)25:06
- Review: Dot Diagrams7:10
- Review: Ion Formation8:30
- Ionic Bond9:57
- Ionic Bond9:58
- Sodium and Fluorine10:41
- Magnesium and Chlorine16:30
- Covalent Bond22:19
- Covalent Bond22:20
- Hydrogen and Carbon23:58
- Hydrogen and Oxygen27:28
- Multiple Covalent Bonds29:03
- Single Covalent Bond29:04
- Double Covalent Bond29:40
- Triple Covalent Bond31:50
- Polar and Nonpolar Molecules33:33
- Polar Molecules33:34
- Unequal sharing of Electrons and Electronegativities35:02
- Nonpolar Molecules37:46
- Example 1: Elements and Atoms38:42
- Example 2: Dot Diagram of the Bond That Forms Between Magnesium and Oxygen41:17
- Example 3: Dot Diagram of the Bond That Forms Between Nitrogen and Oxygen45:24
- Example 4: Polar or Nonpolar?47:22

Chemical Bonding, Part 2

56m 22s

- Intro0:00
- Bonding Atoms Make Compounds0:05
- Binary Compounds0:06
- Reviwew: Oxidation Number1:14
- Naming Ionic Compounds1:45
- Naming Ionic Compounds1:46
- NaCl2:26
- MgCl25:04
- Al2S36:52
- Writing Formulas of Ionic Compounds10:03
- Writing Formulas of Ionic Compounds10:04
- Beryllium Fluoride10:17
- Lithium Nitride12:24
- Calcium Bromide13:53
- Polyatomic Ions15:31
- Polyatomic Ions15:32
- Ammonium Phosphate17:21
- Aluminum Hydroxide19:37
- Magnesium Chlorate20:54
- NaOH21:47
- (NH4)2O22:17
- Mg(NO3)222:56
- Special Ions23:28
- Iron (III) Iodide24:28
- Lead (IV) Chloride26:30
- Chromium (III) Oxide27:31
- Fe3P229:18
- CuI231:51
- PbBr233:04
- Naming Covalent Compounds33:57
- Naming Covalent Compounds33:58
- Examples35:03
- Ionic or Covalent?39:50
- Ionic vs. Covalent: Electron39:51
- Ionic vs. Covalent: State At Room Temperature10:23
- Ionic vs. Covalent: Metal, Nonmetal, Metalloids41:02
- Ionic vs. Covalent: Naming41:35
- Example 1: Write the Names or Formulas for Each Ionic Compound42:50
- Example 2: Write the Names or Formulas for Each Covalent Compound46:13
- Example 3: Name the Following Ionic Compounds49:44
- Example 4: Provide the Formulas for the Following Ionic Compounds52:19
- Example 5: Ionic or Covalent?54:21

Chemical Reactions

49m 13s

- Intro0:00
- Chemical Reactions0:05
- Chemical Reactions0:06
- Chemical Formula Example0:54
- Reactants and Products3:50
- Conservation of Mass4:58
- The Total Mass of the Reactant Must Equal the Total Mass of the Products4:59
- Balancing Chemical Equations6:42
- Balancing Equations11:12
- Example 1: Balancing Equations11:27
- Example 2: Balancing Equations14:15
- Example 3: Balancing Equations16:28
- Types of Reactions19:17
- Synthesis19:18
- Decomposition20:09
- Single-Displacement20:54
- Double-Displacement22:12
- Combustion23:34
- Energy in Chemical Reactions24:41
- Chemical Reactions and Activation Energy24:42
- Endergonic Reactions25:55
- Exergonic Reactions27:51
- Rate of Chemical Reactions29:42
- Rate of Chemical Reactions Overview29:43
- Temperature30:51
- Concentration31:26
- Agitation32:08
- Surface Area32:29
- Pressure33:06
- Catalysts and Inhibitors33:18
- Example 1: Translate Into Chemical Equations34:32
- Example 2: Law of Conservation of Mass37:35
- Example 3: Balance the Following Equations40:33
- Example 4: Math Each Equation With the Correct Type of Reaction44:58
- Example 5: Exothermic or Endothermic Reaction?48:21

Solutions, Acids, and Bases

29m

- Intro0:00
- Solutions0:06
- Definition of Solution0:07
- Solute and Solvent0:26
- Example: Salt Water0:35
- Example: Carbonated Water1:03
- Dissolving1:49
- Dissolving1:50
- Example: Liquid Dissolves a Solid at the Surface of the Solid3:54
- Aqueous Solutions: Water as Solvent4:42
- Increasing the Rate of Dissolving5:33
- Stir5:34
- Crush6:37
- Heat7:36
- Solubility8:31
- Definition of Solubility8:32
- Compare the Solubility of Sugar in Water vs. Salt in Water8:44
- Factors that Affect Solubility11:45
- Concentration12:45
- Concentration12:46
- pH Scale15:21
- pH Scale: Acids, Neutral, and Bases15:22
- Acids and Bases18:01
- Chemical Properties18:02
- Physical Properties18:43
- pH Scale19:31
- Examples of Acids and Bases19:36
- Acids and Bases React Together to Form Salt and Water20:09
- Example 1: Identify the Solutes and Solvents for the Following Solutions21:26
- Example 2: Temperature and the Rate of Dissolving/Solubility of a Solid23:57
- Example 3: How Can You Make a Solution Have a Higher Concentration?25:44
- Example 4: Acids and Bases27:57

Section 2: Physics

Waves

42m 35s

- Intro0:00
- Waves0:05
- Introduction to Waves0:06
- Mechanical Waves1:24
- Electromagnetic Waves1:50
- Mechanical Waves2:13
- Transverse2:14
- Longitudinal (Compressional Waves)4:00
- Properties of Waves7:26
- Transverse and Compressional Waves: Wavelength7:27
- Transverse and Compressional Waves: Frequency (Hz)9:32
- Transverse and Compressional Waves: Amplitude11:30
- Wavelength and Frequency are Related13:40
- Wave Speeds15:01
- Wave Speeds15:02
- Behavior of Waves18:06
- Reflection18:33
- Refraction22:42
- Diffraction24:25
- Electromagnetic Waves26:00
- Electromagnetic Waves26:01
- Visible Light30:49
- Visible Light30:50
- Opaque34:25
- Translucent34:54
- Transparent35:41
- Example 1: Label the Transverse Wave36:59
- Example 2: Label the Compressional Wave38:13
- Example 3: What Happens to the Frequency of a Wave as the Wavelength Increases?39:12
- Example 4: Law of Reflection and Light Wave40:48

Motion

37m 21s

- Intro0:00
- Distance vs. Displacement0:04
- Distance0:05
- Displacement0:49
- Speed4:47
- Speed4:48
- Instantaneous Speed6:14
- Average Speed6:40
- Velocity7:25
- Distance-Time Graphs8:21
- Distance-Time Graphs8:22
- Acceleration13:38
- Acceleration Definition13:39
- Acceleration Equation15:23
- Positive Acceleration18:43
- Negative Acceleration18:52
- Speed-Time Graphs20:56
- Speed-Time Graphs20:57
- Example 1: Displacement, Distance, and Average Speed25:15
- Example 2: Velocities28:02
- Example 3: Acceleration28:59
- Example 4: Distance and Time30:19
- Example 5: Speed and Time34:08

Forces

35m 3s

- Intro0:00
- Force0:04
- Force Definition0:05
- Net Force1:44
- Balanced Forces3:06
- Unbalanced Forces4:23
- Forces Examples5:09
- Friction7:53
- Friction Definition7:54
- Static Friction8:23
- Sliding Friction9:35
- Rolling Friction10:11
- Fluid Friction11:13
- Air Resistance12:10
- Newton's Laws of Motion14:06
- First Law of Motion14:07
- Inertia15:56
- Newton's Laws Continued17:13
- Second Law of Motion17:14
- Third Law of Motion18:35
- Gravitational Force24:17
- Gravity and Gravitational Force24:18
- Example 1: Horizontal Force, Frictional Force, and Net Force28:36
- Example 2: Net Force and Acceleration29:38
- Example 3: Gravitational Force30:35
- Example 4: Force of Air Resistance and Net Force32:32

Density & Buoyancy

23m 43s

- Intro0:00
- Density0:05
- Definition of Density0:06
- Density = Mass / Volume1:01
- Density of Irregular Objects3:58
- Density of Irregular Objects3:59
- Buoyant Force7:46
- Buoyancy7:47
- Archimedes' Principle9:23
- Floating and Sinking12:47
- Floating and Sinking: Looking at Density12:48
- Example 1: Density of an Object16:15
- Example 2: Density of Yourself17:28
- Example 3: Using Archimedes' Principle to Predict If an Object Will Sink or Float in Water19:38
- Example 4: Will Aluminum, Gold, and Oil Float or Sink When Placed Into Water?22:06

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For more information, please see full course syllabus of Physical Science

For more information, please see full course syllabus of Physical Science

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0 answers

Post by Oscar Zhou on April 9 at 01:38:04 PM

When you are finding the density of yourself, which is mass divided by volume. Is the mass same as the weight? When you put yourself on a scale, will it give me my weight, but not the mass? I remember that the weight is mass multiplied by the gravitational acceleration, so I think that you should divide the weight by the gravitational acceleration to get your mass, is that correct?

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Post by Yisrael Harris on May 5, 2013

I have completed the entire Physical Science course, and I would like to say that I enjoyed it very much.

1 answer

Last reply by: Professor Ebs

Thu May 2, 2013 10:03 PM

Post by Yisrael Harris on May 2, 2013

What if an object's density equals exactly that of water?

0 answers

Post by Saakshi Dhingra on April 14, 2013

Does the temperature of the water affect the weight of the amount of displaced water?

0 answers

Post by shaminder makh on April 6, 2013

very helpful

0 answers

Post by Nathanael Shim on December 7, 2012

wow this lesson is so cool...