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Presentation Slides & Transcript
Presentation Slides & Transcript
Nature of EnergyWhat is energy that it can be involved in so many different activities?Energy can be defined as the ability to do work.If an object or organism does work (exerts a force over a distance to move an object) the object or organism uses energy.
Forms of EnergyThe five main forms of energy are:HeatChemicalElectromagneticNuclearMechanical
Kinetic and Potential Energy
Potential Energy…Energy due to position or stored energy.Stored chemically in fuel, the nucleus of atom, and in foods.Measure by:PE= (weight) (gravity) (Height)Potential energy is calculated by:The object’s weight, multiplied by the earth’s gravitational pull (9.8 m/sec sq), multiplied by the distance the object can fall.
Potential EnergyPotential Energy is stored energy.Stored chemically in fuel, the nucleus of atom, and in foods.Or stored because of the work done on it:Stretching a rubber band.Winding a watch.Pulling back on a bow’s arrow.Lifting a brick high in the air.
Examples of Potential Energy:Stretching a rubber band.. -Stores energyWater at the top of a waterfall.. -Stores energy Yo–Yo in held in your hand.. -Stores energy because of positionDrawing a Bow… -Stores energy because of position
Potential EnergyEnergy that is stored due to being stretched or compressed is called elastic potential energy.
Gravitational Potential EnergyPotential energy that is dependent on height is called gravitational potential energy.
Gravitational Potential EnergyA waterfall, a suspension bridge, and a falling snowflake all have gravitational potential energy.
Gravitational Potential EnergyIf you stand on a 3-meter diving board, you have 3 times the G.P.E, than you had on a 1-meter diving board.
Potential Energy Converted to Kinetic Energy…When stored energy begins to move, the object now transfers from potential energy into kinetic energy.Standing stillRunning
Definition of Kinetic Energy…The energy of motion.Measured by:KE= ½ (Mass) (Velocity)2Kinetic energy is calculated by one half of the object’s mass,multiplied by the object’s speed- squared.
Examples of Kinetic Energy…Shooting a rubber band.Water falling over the fall.A Yo-Yo in motion.Releasing the arrow from the bow.
Kinetic-Potential Energy ConversionRoller coasters work because of the energy that is built into the system. Initially, the cars are pulled mechanically up the tallest hill, giving them a great deal of potential energy. From that point, the conversion between potential and kinetic energy powers the cars throughout the entire ride.
Kinetic-Potential Energy ConversionsAs a basketball player throws the ball into the air, various energy conversions take place.
Ball slows downBall speeds up
The Law of Conservation of EnergyEnergy can be neither created nor destroyed by ordinary means.It can only be converted from one form to another.If energy seems to disappear, then scientists look for it – leading to many important discoveries.
Mechanical EnergyWhen work is done to an object, it acquires energy. The energy it acquires is known as mechanical energy.
Mechanical EnergyWhen you kick a football, you give mechancal energy to the football to make it move.
Mechanical EnergyWhen you throw a balling ball, you give it energy. When that bowling ball hits the pins, some of the energy is transferred to the pins (transfer of momentum).