THE ABILITY TO CAUSE CHANGE1

mechanical energyTypes of Energy2

EnergyEnergy is the capacity (ability) to do work. Kinetic Energy: Associated with an object in motionPotential Energy: Present in an object that has the potential to move because of its position

4CLIP

Kinetic EnergyMotionKE of an object depends upon two variables: the mass (m) of the objectthe speed (v) of the object.

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A formula to find the kinetic energy of any body based on its velocity.Calculating Kinetic Energy6

Potential EnergyAn object can store energy as the result of its position.

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Forms of potential energy-position above the Earths surface-stored in something stretchy-chemical reaction8

Gravitational Potential EnergyGPE is the energy stored in an object as the result of its vertical position (i.e., height). Amt. of GPE is dependent on two variables:the massthe height

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Calculating Gravitational Potential Energy10

Conservation of Energy Energy cannot be created or destroyedonly changed from one form to another.

The total energy of an isolated system remains constant (isolated systems have no external forces and no mass changes)13

14ENERGY BEFORE = ENERGY AFTER

Energy can be changed from one form to another, but it does not disappear.

Mechanical EnergyThe motion of some objects contain a combination of only kinetic and potential energies.ME is the sum of the KE and forms PE associated with a systemTherefore, ME= KE + PE15

TOTAL ENERGY OF THE SYSTEM REMAINS THE SAMEConservation of Energy 16

Conservation of Energy TOTAL ENERGY OF THE SYSTEM REMAINS THE SAME17

This dolphin has lots of kinetic energy as it leaves the water. At its highest point its energy is mostly potential energy.

Conservation of Mechanical Energy:

Therefore, MEi = MEf

KEi + PEi = KEf + PEf mvi2 + mghi = mvf2 + mghf

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The sum K + Ug is not changed when an object is in free fall. Its initial and final values are equal:

Conservation of Mechanical Energy:Conservation of ME only hold true when the only energies of the system are KE and PE.Therefore, in the presence of friction energy is transformed to other types of energies.19

Elastic Potential Energy

Spring stores energy

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