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Potential and Kinetic Energy. What is Energy???. The ability of an object To do work. Kinetic Energy. Potential Energy. Elastic Potential Energy. Gravitation Potential Energy. Chemical Potential Energy. Two Main Types of Energy. All Energy. What is Potential Energy?.
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What is Energy??? The ability of an object To do work
Kinetic Energy Potential Energy Elastic Potential Energy Gravitation Potential Energy Chemical Potential Energy Two Main Types of Energy All Energy
What is Potential Energy? • Energy that is stored and waiting to be used later
What is Gravitational Potential Energy? • Potential energy due to an object’s position • P.E. = mass x height x gravity Don’t look down, Rover! Good boy!
ARRGGGG!! NO TRIANGLE Gravity PE Mass Height
Find the Potential energy of a 20 kg bag of dog food elevated 5 meters above the ground on a shelf. Mass = 20 kg PE = mx g x h Height = 5 m PE = 20 kg x 9.8 m/s2 x 5 m PE = 980 J
Find the potential energy of a 65 kg climber on top of Mt. Everest ( 8800 m high). Mass = 65 kg PE = mx g x h Height = 8800 m PE = 65 kg x 9.8 m/s2 x 8800 m PE = 5 605 600 J
What is Elastic Potential Energy? • Potential energy due compression or expansion of an elastic object. Notice the ball compressing and expanding
What is Chemical Potential Energy? • Potential energy stored within the chemical bonds of an object
What is Kinetic Energy? • Energy an object has due to its motion • K.E. = .5(mass x speed2)
Kinetic Energy Depends on … Mass and Speed
KE = ½ mass x velocity2 KE = ½ M X V2 What is the kinetic energy of a 44kg cheetah running at 31 m/s? KE = ½ M x V2 Mass = 44 kg Speed = 31 m/s KE = .5 x 44 kg x (31 m/s)2 KE = 21 142 J
KE = ½ mass x velocity2 KE = ½ M X V2 What is the kinetic energy of a 400kg elevator descending at a rate of 5 m/s? KE = ½ M x V2 Mass = 400 kg KE = 400 kg x (5 m/s)2 Speed = 5 m/s KE = 5 000 J