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Glossary of God's Design for the Physical World: Heat and Energy

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What is the scientific defintion of energy?
The ability to do work
What are the eight types of energy recognized by scientists?
Mechanical, chemical, nuclear, thermal, electrical, magnetic, sound, and light
Which types of energy can be converted into other types of energy?
Pretty much all forms can be converted, although it is unlikely to convert most forms of energy into nuclear energy.
What is mechanical energy?
The energy of moving objects
What are the two forms of mechanical energy?
Kinetic and potential
What are some forces in nature that possess mechanical energy?
Wind, waves, volcano, animals, any object that is higher than ground level, anything that is moving
What is chemical energy?
Energy that is stored in the bonds of molecules
What two complementary processes were designed by God to change the sun's energy into energy for all living things?
Photosynthesis and digestion/cellular respiration
Name two fossil fuels.
Petroleum/oil, coal, and natural gas.
Other than digestion, what is the most common way to release chemical energy?
Through combustion or burning
What is nuclear power?
Energy that is released when the nucleus of an atom is changed.
What is nuclear fission?
A nucleus splits apart after being hit by a speeding neutron.
What is nuclear fusion?
When a new nucleus is formed by the fusing of two or more smaller nuclei or nuclear particles such as protons and neutrons.
Which nuclear process is used in nuclear power plants?
Nuclear fission
What are the two types of nuclear weapons that have been developed?
Fission and fusion
Why are fusion bombs sometimes called hydrogen bombs?
Energy is released as hydrogen atoms fuse to form helium.
Why are fusion bombs sometimes called thermonuclear weapons?
The fusion reaction occurs at very high temperatures.
How are the high temperatures needed for a fusion reaction achieved in a hydrogen bomb?
A small fission reaction is used to produce the temperatures.
What is thermal energy?
The total energy in an item due to the movement of the item's molecules.
What is temperature?
The average energy the molecules contain.
What is a calorie?
The amount of energy needed to raise 1 gram of water 1 degree Celsius.
How are Calories in food related to thermal energy?
The number of Calories the food contains is the potential energy stored in the food. This represents the amount of thermal energy it can supply.
What is conduction?
The transferring of heat energy by the collision of faster molecules with slower molecules.
What is equilibrium?
When two substances have transferred energy until they are both at the same temperature--they both have the same average thermal energy.
Which materials are good conductors of heat?
Metals are good conductors of heat, and silver is the best conductor.
What is convection?
The movement of heat by currents
What causes convection?
Gravity causes denser materials to sink below lighter materials.
How does convection affect the weather on earth?
Heat from the sun causes convection currents in the air, resulting in winds and movement of weather systems.
What is thermal radiation?
It is heat that is transferred by way of electromagnetic waves.
Which type of electromagnetic waves most easily transfer heat energy?
Infrared waves
Which colors best absorb radiated heat?
Dark colors, especially black.
What is solar energy?
Energy from the sun.
What is geothermal energy?
Heat energy from beneath the surface of the earth.
How is solar energy used?
The radiation is used to heat water in solar panels for use in the home. Also, solar energy can be used to generate electricity.
How is geothermal energy used?
The heat from the earth is used to generate steam.
What is electricity?
The flow of electrons.
What is static electricity?
An electrical charge that is built up on an object.
What is the Law of Charges?
Opposite charges attract, like charges repel.
What is an electrical conductor?
A material that easily allows electrons to flow.
What is an electrical insulator?
A material that does not conduct electricity easily.
What is a semi-conductor?
A material that allows a small amount of electricity to flow through it.
What materials are good conductors of electricity?
Metals
What materials are good electrical insulators?
Wood, plastic, rubber, cloth, etc.
What is lightning?
A sudden discharge of electricity.
What causes lightning?
Friction between rapidly moving air, water drops, ice and hail strips electrons from the particles causing clouds to build up a static charge.
What is thunder?
The sound generated by rapidly expanding air in a thunderstorm.
What causes the air molecules to move quickly enough to generate thunder?
The enormous amount of heat generated by the flow of electrons in a lightning bolt.
What is current?
A continuous flow of electrons.
Name two ways to generate current.
Chemical reaction such as with a battery, with an electromagnet like at a power plant, or with lightning.
What is a circuit?
It is a complete path or circle through which current can flow.
What is a short circuit?
When current finds a shorter path back to its source without going through the intended device.
What is voltage?
It is a measure of the electrical potential energy that can be supplied by a battery or other power source.
What direction does current flow in a battery?
It flows from the negative terminal to the positive terminal.
Describe the difference between a serial circuit and a parallel circuit.
A serial circuit has only one path for the current to flow through; a parallel circuit has multiple paths for the current to flow through.
What is a magnet?
A material in which most of the atoms are lined up in the same magnetic orientation.
Is the strength of a magnet the same throughout the magnet?
No, the field is strongest near the poles.
What is the Law of Magnetic Poles?
Opposite magnetic poles attract and same poles repel.
What materials are magnetic?
Iron, cobalt, nickel, gadolinium, and alloys with these materials.
How can a magnet lose its magnetism?
A sharp blow can cause the atoms to become randomly aligned and thus lose the magnetic field.
Do all magnetic materials produce the same strength magnetic field?
No, some magnets are stronger than others.
How is the earth like a giant magnet?
It has a magnetic field with a north and south pole.
How far does the earth's magnetic field extend?
It goes several hundred miles into space.
Where is the earth's magnetic north pole?
It is in the Arctic Ocean north of Canada and south of the geographic North Pole.
What is an electromagnet?
A magnetic field that is generated when a current passes through a coil that surrounds a magnetic material.
What are some common uses for electromagnets?
Sorting metals, moving magnetic materials, maglev trains, computer disks, video tapes.
What is an electric generator?
A device that produces electricity.
How do most electric generators work?
They use steam to turn a turbine attached to a wire coil that is suspended in a magnetic field. The moving coil creates a changing magnetic field, which induces a current to flow in a nearby wire.
What is an electric motor?
A device that changes electricity into mechanical energy.
How does an electric motor work?
A changing current flows through a coil that is suspended in a magnetic field. This creates a changing feild that repels the coil and makes it spin, thus producing mechanical energy.
What are two different types of energy waves?
Mechanical and electromagnetic, or light and sound.
What is the main difference between mechanical and electromagnetic waves?
Mechanical waves must have a medium to transport them and electromagnetic waves can move through a vacuum.
What is the highest point of a wave called?
The peak or crest
What is the lowest part of a wave called?
Thr trough.
How is a wavelength of a wave defined?
The distance from one peak to the next peak.
What characteristic of an electromagnetic wave determines its visible color?
Its frequency or wavelength.
Which waves have a higher frequency, radio waves or gamma rays?
Gamma rays
Which kinds of electromagnetic waves are used for communication?
Primarily radio waves, but some communications use microwaves.
What is a sound wave?
An energy wave that is detectable by the human ear.
How do sound waves move through the air?
By causing the air molecules to compress and expand as the wave passes through.
List some materials through which sound waves can travel.
Air, water, metal, wood, the ground, and many other items...
What types of materials absorb sound waves?
Cloth and other porous materials--materials with many holes in them.
What are the three main characteristics that determine the quality of a sound?
Pitch or frequency, loudness or amplitude, and overtones or harmonics.
How does the pitch change as the frequency goes up?
The pitch goes up--gets higher.
What is an overtone?
It is a secondary wave traveling with the primary wave that has a frequency that is a multiple of the primary frequency.
What units are used to measure loudness?
Bels or decibles.
What are acoustics?
A building's effects on sound.
What is resonance?
When one vibrating material transfers its energy to another material with the same natural frequency.
What is the Doppler effect?
The pitch of an object increases as the source approaches and decreases as it goes away from you.
What makes music different from noise?
The notes are distinct. They have specific pitches and timing. Music has rhythm.
What are the four main types of instruments? How does each make a tone?
Strings--a string is vibrated
Percussion--a surface vibrates when struck
wind--air is made to vibrate by blowing
electronic--vibrations are converted into electrical signals that are amplified and turned into sound waves
How is a light wave different from a sound wave?
It is at a higher frequency and can travel through a vacuum. It is electromagnetic, not mechanical.
Name three sources of light.
The sun, flames, light bulbs, etc...
What color of light has the lowest frequency? What color has the highest frequency?
REd has the lowest frequency and violet has the highest frequency.
Explain how an incandescent bulb produces light.
It contains a thin wire made of a material (like tungsten) that glows when a current passes through it.
Explain how a fluorescent bulb produces light.
Electricity excites the gas inside, turning it into plasma. The plasma emits ultraviolet light that causes the phosphor inside the bulb to glow.
What is the true color of white light?
It contains all colors of visible light.
Why does light split when it goes through glass or water?
Different colors of light travel at different speeds through different materials, so the rays of light are bent different amounts as they pass through water/glass/etc.
How do our eyes detect light?
Special cells called rods and cones detect light and send signals to the brain.
What color of light does a yellow object absorb?
All wavelengths except yellow.
What is a reflection?
Light that bounces off of a surface.
Which types of materials best reflect light?
Smooth and shiny materials.
What kind of path does light take?
It moves in waves that travel in straight lines.
What are the three shapes of mirrors?
Plane or flat, concave, and convex.
How does a concave mirror affect light rays and the reflected image?
It bends the light inward and inverts the image (turns it upside-down).
How does a convex mirror affect the light rays and the reflected image?
It bends the light outward and stretched the image.
What is refraction?
The bending of light as it changes speeds going from one medium to another.
Why do items appear to be in a different location underwater than they actually are?
The bent light hits your eyes in a location other than where you expect, making the object appear to be in a slightly different location.
What is a mirage?
It is a reflection of the sky above the pavement on a hot day. It occurs because light is bent as it moves from denser cooler air into warmer less dense air near the ground.
What is a lens?
A curved piece of glass or plastic that bends light.
What effect does a convex lens have on light?
Parallel light rays are bent toward the center of the lens. Images are either upside down and smaller than the actual object, or right side up and larger, depending on the distance from the lens and the lens's focal length.
What is another name for a concave lens?
Diverging lens.
Name three inventions that use lenses.
Telescope, microscope, camera, eyeglasses, magnifying glass (and others)
What effect does a concave lens have on light?
Parallel light rays are bent outward from the lens. The image will be right-side-up and smaller.

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