Energy 1 Energy The ability to do work

Energy

1. Energy • The ability to do work or cause change is called energy.

1. Energy • When an object does work on another object, energy is transferred to that object • Power is the rate at which the work is done.

2. Types of Energy • There are two basic kinds of energy: – Kinetic Energy – Potential Energy

3. Kinetic • The energy of motion is called kinetic energy (kineos = moving) Ex: running, blowing, rolling, sliding

4. Potential • Stored energy, based on the position or mass of an object is called potential energy. • Potential Energy Depends on – Position – Mass of object Ex: sitting on a shelf / sitting on the floor small car sitting on a hill large car sitting on a hill

5. Types of Potential Energy • Gravitational Potential Energy is energy related to an objects height. • Ex: a skier on a 100 ft. slope has more potential energy than a skier on a 70 ft. slope

5. Types of Potential Energy • Elastic Potential Energy is energy gained from being stretched • Ex: sling shot, bow and arrow

Forms of Energy

1. Mechanical • Energy associated with the position and motion of an object (working energy) • Mechanical energy = PE + KE Ex: a football being thrown by Drew Brees vs. being thrown by a 4 year old boy (size of ball, strength of player)

2. Thermal • Particles in motion generate heat – which is measured by thermal energy Ex: fast moving particles – high heat slow moving particles – less heat fire, lava, warm air, sunlight

3. Electric • Energy from electric charges – or the movement of electrons Ex: electricity in your home lightning batteries

4. Chemical • Energy that comes from breaking and forming chemical bonds Ex: fizzing caused by baking soda and vinegar glow sticks producing light food

5. Nuclear • Potential energy that is stored in an atom and released in a nuclear reaction Ex: electricity from nuclear power plant nuclear fission

6. Electromagnetic • Energy that travels in waves Ex: microwaves sunlight xrays radio waves sound

Energy Transformations and Conversions

1. Energy Transformations • Most forms of energy can be transformed into other forms. This is called an energy transformation. • Two types of energy transformations are: – Single transformations – Multiple transformations

2. Single Transformations • In a single transformation, one form of energy is transferred into another. • Examples: – Toasters transform electrical to thermal – Cell phones transform electrical to electromagnetic – Your body transforms chemical to mechanical

3. Multiple Transformations • Multiple transformations occur when a series of energy transformations occur. • Example – Striking a Match: – Mechanical to strike it – Thermal energy releases stored chemical energy – Electromagnetic energy in the form of light

4. Conservation of Energy • The law of conservation of energy states that energy can not be created or destroyed.

Heat Transfer

1. Conduction • The transfer of heat by TOUCH • Examples include: – Warm hands by holding hot coffee – Warm seat by sitting on it – Spoon gets hot by sitting in hot soup

2. Radiation • Getting heat by standing near something that is hot • Heat spread out, so it is cooler the farther away you are • Examples: – Heat from hot pavement – Heat from hot grill – Steam off of hot coffee – Standing near a fire

3. Convection • Heat that circulates is called convection • Examples: – a vent blows the heat around a room – Convection oven – heat rises as in boiling water

4. Insulator • An insulator prevents heat from coming in or going out • Examples: – Thermal jacket – Thermal cups / mugs – Home insulation

5. Conductor • Used to transfer heat • Examples: – Metal is a good conductor of heat

What do I study for my test? • Notes Types of Energy • Notes Energy Transformations • Notes on Heat (conduction, radiation, convection) and Insulators and Conductors • Feel the Heat Worksheet • Kinetic or Potential energy Worksheet • What is Heat Worksheet • Vocabulary