Kinetic and Potential Energy
Dec 22, 2015
Law of Conservation of Energy
•Energy cannot be created nor destroyed•Energy can change from one form to
another
•Two Types of Energy▫Kinetic Energy▫Potential Energy
Kinetic Energy
•The energy of motion•When an object is moving it is said to
have kinetic energy▫Ball rolling down a hill
Kinetic Energy•When an object is not moving
▫Ball sitting at the top of a hill or at the bottom No kinetic Energy
Potential Energy
•The energy stored in an object or substance
•An object that is at rest (not moving) has potential energy▫The object can potentially start to move
•Ball rolling down a hill▫No Potential energy
•A ball at the top of a hill or at the bottom, that is not moving▫Potential Energy
Potential Energy
•The amount of potential energy an object has depends on its mass and the height of the object above a surface
•A ball is sitting at the top of the hill▫The potential energy increases as the
height of the hill increases•PE=massg•height•g is a constant due to gravity.
▫On Earth g=9.81 m/s²•Potential Energy unit is joules (J)
Kinetic and Potential Energy
•As potential energy increases Kinetic Energy increase
Potential Energy
Kinetic Energy
Transferring of Energy
•Law of conservation of Energy says that energy cannot be created or destroyed just changes from one form to another.
•Energy transfers from Potential energy(object at rest- the potential to move) to Kinetic Energy (an object in motion)
VariablesIndependent Dependent
• The item that is changed in the experiment
• Height of the ball
• The item that is being measured in the experiment
• The distance the ball traveled
Transferring of energyHand and Block Pendulum
• Kinetic energy was transferred from the moving hand to the wooden block
• Potential energy was converted to Kinetic Energy
• The Potential energy of the pendulum ball was transferred to Kinetic energy of the ball as it was dropped from its starting position
• The kinetic energy was transferred to the ball, causing the ball to move.
Electrical Energy
•Electric Potential Energy- the potential energy that exists when comparing a region of high electrical charge to one of low electrical potential charge
•Electric Power is the rate a which electrical potential energy is converted into other forms
Light Energy
•Light energy is a form of Kinetic Energy ▫Photons in light move
•Light bulbs are given power rating in watts (W)
•When wattage of a light bulb increases the light intensity increases
•Wattage increases=electrical energy increases
Electrical and Light EnergyElectrical Energy (potential Energy)
Light Energy (Kinetic Energy)
• One form of energy is converted to another form of energy▫ Electrical Energy Light energy▫ Potential Energy Kinetic Energy
Light Energy Converted To
•Thermal (heat)•Solar (back to electrical energy)•Chemical (photosynthesis)
Can one form of energy be converted to another?•Yes, Energy can be converted to other
forms▫Potential to Kinetic▫Electrical to Light▫Light to Heat▫Light to Chemical▫Light to Electrical
Converting Energy and Law of Conservation of Energy•Law of conservation of energy says
energy can be converted from one form to another,
•But it is not created or destroyed▫Increase in electrical energy (wattage)
shows an increase in the light energy and temperature (heat) shows that energy was conserved
Chemical Potential Energy
•the potential energy stored in the chemical bonds of chemical compounds
•This energy can be released when substances react chemically to form new substances▫Backing soda + vinegar=carbon dioxide
Chemical Potential energy
•Baking soda has chemical Potential Energy
Vinegar has chemical potential Energy▫The energy is released when the reactions
starts•Once the reaction begins the potential
energy becomes kinetic
•Potential Energy that was stored in the baking soda and the vinegar is converted into Kinetic Energy
Chemical Energy
•As the amount of Vinegar increases to react with the baking soda the more chemical energy that is released
•Increase in Chemical energy relased▫More bubbles▫Occurred faster
•Increasing either the vinegar or baking soda increases the potential energy thus increasing the Kinetic energy