Energy, Work, and Power By: Boniquit, Ross Mignonette & Tan, Bernadette B. ACS2A

Energy Ancient Greek: energeia meaning "activity, operation" Is the Ability to Do Work. SI unit of energy = joule (J) Energy = Power x Time

Nature of Energy Energy is all around you! –You can hear energy as sound. –You can see energy as light. –And you can feel it as wind.

Nature of Energy You use energy when you: –hit a softball. –lift your book bag.

Nature of Energy Energy is involved when: –a bird flies. –a bomb explodes. –rain falls from the sky. –electricity flows in a wire.

Types of Energy Kinetic Energy –Energy of motion. –The faster an object moves and the greater the mass of a moving object, the more kinetic energy it has. –Examples: Ball dropping Electricity Potential Energy –Stored energy. –Examples: Pulling back on a bow’s arrow. Lifting a heavy ball high in the air.

Forms of Energy The five main forms of energy are: –Heat or Thermal Energy the vibration and movement of the atoms and molecules within substances. –Chemical Energy energy stored in the bonds of atoms and molecules. –Electrical Energy delivered by tiny charged particles called electrons, typically moving through a wire. –Nuclear Energy energy stored in the nucleus of an atom — the energy that holds the nucleus together. –Mechanical Energy energy stored in objects by tension.

Work The transfer of energy through motion. Using a force to move an object. Unit of work = joule (J) Work = Force x Distance Examples: A person lift a box to a height of 1m with 5N of force, he is doing some work and his work is 5N.

Simple Machines A machine is a device that helps make work easier to perform by accomplishing one or more of the following functions: transferring a force from one place to another, changing the direction of a force, increasing the magnitude of a force, or increasing the distance or speed of a force.

Levers help us lift weights with less effort. For example: scissors, can opener, fork, stapler

Makes it easier to slide a load upward than to lift it directly. For example: a ramp may be used when loading or unloading heavy objects out of a delivery truck.

A wedge is closely related to the inclined plane. A wedge can be used to lift a heavy load over a short distance or to split things into two pieces. For example: knife, shovel

A screw is simply an inclined plane that is wrapped around a cylinder or a cone. The main purpose is to raise a load over the threads, which is the spiral part of the screw, by applying a small force.

A pulley changes the direction of a force and uses grooved wheels and a rope to raise, lower or move a load. For example: flagpole

Power Rate of doing work Unit of power = watt (W) Power = Work / Time

Types of Power Electrical Power Uses electrical energy to do work. Mechanical Power Uses mechanical energy to do work. Fluid Power Uses energy transferred by liquids and gases.