Electric Math: The Numbers and Math Behind Our Everyday Appliances

Have you ever looked over the details on your utilities bills to compare how much energy you use each month, compared to previous months? Every electrical appliance in your home uses a source of power. When household appliances, such as the television or lamp, is left on, electricity is being used and this energy costs money. Here you will learn about how to read an electric meter, how much energy costs, math conversions and formulas containing to energy use, how we can save energy, and much more.

What Do the Numbers Mean?

  • Ampere (Amp) – The measure of a unit of steady electric current that passes a point per unit time.
  • Horsepower – Several units of measurement of power equivalent to 550 foot-pounds per second, or 745.7 watts.
  • Kilowatt Hours – Unit of energy equal to 3.6 megajoules or 1000 watt hours.
  • OHM – The SI unit of electrical resistance between two points of a conductor with a difference of 1 volt.
  • Voltage (Volt) – The SI unit of volts across a conductor when a one ampere current dissipates one watt of power.
  • Watt – Derived unit of power that measures the rate of energy conversion defined in one joule per second.
  • Kilowatt – Measure of 1000 watts of standard electrical power or an energy consumption rate of 1000 joules.
  • Megawatt – Measure of 1 million watts of standard electrical power or one joule per second.

Formulas and Conversions

  • Power Calculators: Here you will find several power calculators that provide instant formulas for converting Watts, Kilowatts, KVA, Voltage and Amps.
  • Electrical Formulas: List of formulas used for the conversion of Volts, Watts, Amps, KVA, KW and Horsepower.
  • Conversion Formulas: Guide to formulas and documentation of electrical values and their conversions.
  • Measuring & Converting Energy: Here you will find conversion and resource tables used to convert Foot-pounds, Joules, calories, Kilo-calories and Kilowatt-hours.

How Much Electricity Do We Use?

  • Electric Meters: Learn about electric meters and how to read yours to determine how much energy is being used in your home.
  • Standby Power: Learn how much electricity is being used when your electrical appliances are plugged in, but not being used.
  • Energy Consumption: Information and charts showing how much non-renewable energy sources we use, according to fuel type.

How Much Does Energy Cost?

  • Appliance Energy Data: Here you will find the energy costs of running various brands of common appliances in your home.

How Much Energy Can We Save?

  • Conserve Energy: List of 20 things you can do in your home in order to save money and conserve energy.
  • 101 Ways to Save Energy: Here you will find simple ways to save energy in your home with saving tips for each room of the house.
  • Ways to Conserve Energy: Find information on how to save on lighting, home electronics, laundry, dishwashers, cooking, heating, and more.
  • Energy Star: Learn about the amount of money that can be saved when switching to Energy Star windows, doors, and skylights.

Teacher Resources

  • Electrical Appliances: Teacher’s guide to electrical appliances with lesson plans, objectives and activities.
  • Energy Kids: Here you can find lesson plans, submit a lesson plan, get ideas for field trips, and print energy information.
  • Power Up: Useful electricity information for kids ages 7 through 14, as well as parents and teachers.
  • Energy and Electricity: Objectives, materials and procedures listed for this lesson plan, designed for grade levels 6 through 8.
  • Science Topics: Here you will find energy related online lesson plans, worksheets, activities, and quizzes for ages 5 through 11.
  • Lesson Plan Ideas: List of various energy lesson plans and activities designed for individual students or groups.
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