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3.2 Potential and Kinetic Energy. Date, Section, Pages, etc. Mr. Richter. Agenda. Warm – Up Review: What is Energy? Notes: What is Energy Units of Energy Potential Energy Kinetic Energy Tests Returned. Objectives: We Will Be Able To…. Define potential and kinetic energy.
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3.2 Potential and Kinetic Energy Date, Section, Pages, etc. Mr. Richter
Agenda • Warm – Up • Review: What is Energy? • Notes: • What is Energy • Units of Energy • Potential Energy • Kinetic Energy • Tests Returned
Objectives: We Will Be Able To… • Define potential and kinetic energy. • Calculate potential and kinetic energy
Warm-Up: • Two objects of equal mass sit on two different window sills. One sits on a second floor window and one sits on a fifth floor window. Which object, if either, has more energy? Why? • On a separate sheet of paper, write your name, then 2-3 sentences explaining your thinking. You have 5 minutes.
Energy • Review: Energy is a quantity that measures the ability to cause change. • Energy can cause changes • in motion: like position, speed, and momentum • in physical conditions: like temperature, or turning wood into ashes and smoke • Energy itself cannot be seen or felt, but we can see evidence of energy in other things. • Wind, rolling objects, batteries, gasoline, etc.
Units of Energy • In physics, energy is most commonly measured in Joules [J]. • A Joule is a Newton-meter. [J = N-m] • A Joule is a measure of how much energy is required to push with 1 Newton of force for 1 meter. • Another unit of energy less commonly used in physics is the Calorie. • 1 Calorie = 4187 Joules
Potential Energy • Potential energy is energy due to position. Objects in unstable positions have stored energy. • A stretched spring. • A weight on a window sill. • The most common form of potential energy is energy stored due to the height of an object: gravitational potential energy.
Calculating Potential Energy • Gravitational potential energy (Ep) depends on the mass of the object, and its height above the surface below. • What is the gravitational potential energy of a 10-kg object 5 meters above the ground? • 4900 J
Kinetic Energy • Kinetic energy is energy due to an object’s motion. Moving objects also have the ability to cause change. • The energy of a moving object is equal to the amount of energy that would be needed to stop the object.
Calculating Kinetic Energy • The kinetic energy of an object depends of the mass of that object and its speed. It is closely related to (but not the same as) momentum. • What is the kinetic energy of a 50-kg skateboarder moving at 3 m/s? • 225 J
Wrap-Up: Did we meet our objectives? • Define potential and kinetic energy. • Calculate potential and kinetic energy
Homework • p 69 Your Turn a and b • Science Fair • Notebook and Research due Wednesday • Rough draft of Procedure due Monday 12/3