| Your child comes home with questions about the | | | | partly magnetic. Light moves through the vacuum of |
| different kinds of kinetic energy. So how do you | | | | space or through a material as waves. A wave can |
| distinguish between the many different types? You | | | | be described as a back and forth motion or a |
| can use common examples to help your child | | | | vibration. |
| understand the kinds of kinetic energy. | | | | Light can also move as particles, or photons. |
| Kinetic energy, or the energy of motion, is the ability to | | | | Frequency measures how many complete vibrations |
| do work. If you use a force across a distance, you do | | | | occur in a given time period, usually a second. Hertz is |
| work in a scientific sense. If you slide a book across a | | | | the unit for frequency, named from Heinrick Hertz who |
| table, you have used kinetic energy. The many kinds | | | | demonstrated radio waves, a type of electromagnetic |
| of kinetic energy include mechanical, electrical, radiant, | | | | radiation in 1886. Electromagnetic waves range from |
| and sound. | | | | the longest, radio waves, to the shortest, gamma rays. |
| Four Kinds of Kinetic Energy #1- Mechanical kinetic | | | | The lowest frequency of light that we can see is red |
| energy is the most familiar and common example of | | | | and the highest is violet. AM radio waves are |
| kinetic energy. As an object moves, it has kinetic | | | | broadcast in thousands of hertz, or kilohertz. FM radio |
| energy. In order to lift an orange over your head it | | | | waves are broadcast in millions of hertz, or megahertz. |
| takes a joule of work. Kinetic energy is measured in | | | | Radar and microwave ovens operate in the gigahertz, |
| joules (rhymes with cool) or Newton-meters, with | | | | or billions of hertz range. X-rays and even shorter |
| force measured in Newtons and distance measured in | | | | gamma rays are used in chemotherapy. In a vacuum, |
| meters. A car accelerating at the same rate as a | | | | all electromagnetic waves travel at the speed of light |
| bicycle has more kinetic energy because it has more | | | | which is 300,000 km/s. |
| mass. | | | | Heat energy is another form of radiant energy. If you |
| Four Kinds of Kinetic Energy #2- Electrical energy that | | | | have ever seen a shimmering effect above a paved |
| moves through wires is measured in watts. A joule of | | | | road or parking lot on a hot day, you have seen heat |
| work done in one second is a watt, which is named | | | | waves. You can feel heat radiating from a candle |
| for James Watt, the inventor of the steam engine. | | | | flame, a fireplace, or a space heater. Most light bulbs |
| Trains used to run using steam engines. If you lift a | | | | heat up while they operate because the tiny wire |
| quarter-pound hamburger with cheese vertically, a | | | | inside each bulb, called the filament, heats up and |
| distance of one meter in one second, you use a watt | | | | glows. |
| of power. Take a close look at a light bulb that is not in | | | | Four Kinds of Kinetic Energy #4- Acoustic, or sound, |
| a lamp. You will see a number followed by "kw", or | | | | energy begins with the vibration of an object. A guitar |
| kilowatts, on most light bulbs. Electric motors also have | | | | has strings that vibrate to produce sound. A clarinet |
| kilowatt ratings. A kilowatt is one thousand watts. | | | | has a vibrating reed while a trumpet has a vibrating |
| Electrical power can also be described as the product | | | | column of air in the mouthpiece. The human voice has |
| of current, measured in amperes or amps, and | | | | vocal chords. These vibrations start waves in the air. |
| potential, measured in volts. | | | | However, sound also needs something to move |
| Four Kinds of Kinetic Energy #3- Solar energy is the | | | | through, or a medium. There is no sound in outer space |
| heat and light, or radiant energy produced by the sun. | | | | since there is nothing for it to travel through. |
| The sun does not burn like a fire does. Nuclear fusion | | | | Astronauts outside the space shuttle or the |
| creates the sun's energy. Helium atoms are formed | | | | International Space Station use radio waves, a form of |
| from lighter hydrogen atoms, in the process creating | | | | electromagnetic radiation, to communicate. |
| heat, light, and other particles. | | | | You can use common examples to explain the various |
| Light energy is a form of radiant energy emitted by | | | | kinds of kinetic energy to your child. The many forms |
| accelerating electric charges or the electrons of | | | | of kinetic energy include mechanical, electrical, radiant |
| atoms. Light we see, or visible light, is a small portion of | | | | (heat and light), and sound. |
| electromagnetic waves, which are partly electric and | | | | |