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Do Now Monday, November 18, 2013. Periods 1&2 get ready for your Unit #5 Exam. Afterwards, you will complete your guided notes using the ppt online. 3.5 minutes. Do Now Check. Do Now Monday, November 18, 2013.
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Do Now Monday, November 18, 2013 Periods 1&2 get ready for your Unit #5 Exam. Afterwards, you will complete your guided notes using the ppt online. 3.5 minutes Do Now Check
Do Now Monday, November 18, 2013 What is Newton’s 3rd Law of Motion? Provide a real-world example of Newton’s 3rd Law. 3.5 minutes Do Now Check
By the end of the day today, IWBAT… • Compare and contrast kinetic and potential energy • Calculate kinetic and potential energy Why it matters in LIFE: Energy is what allows us to move! Why it matters in THIS CLASS: This is a HUGE topic that is central to your understanding of everything we will be doing this semester.
Unit 6: Work, Power, and Energy Unit Cover Sheets Trackers
Monday, 11/18/13 Put this into your C-Notes!
What is energy? • ENERGY is the ability to make things move or change • Measured in Joules (J)
Forms of energy • Energy can exist in many different forms and changes from one form to another
Kinetic and Potential Energy • For this unit, we are going to be focusing on the energy of movement • Two main types: Kinetic and Potential
Kinetic Energy • KINETIC ENERGY is the energy of motion • Depends on mass and velocity
Kinetic Energy Which has a higher maximum kinetic energy, my first car or the camaro? Why? The camaro has more KE because it has a higher velocity.
Kinetic Energy Which would hurt more, getting hit by a 15 foot wave or a 2 foot wave? Why? The bigger wave would hurt more because even though they travel at the same speed, the bigger wave has more mass.
Kinetic Energy • Formula: KE = ½mv2 mass (in kg) velocity (in m/s)
Kinetic Energy • The bird has a mass of 2 kg. It is flying at a speed of 5 m/s. Find its kinetic energy. KE = ? m = 2 kg v = 5 m/s KE = ½mv2 KE = ½(2 kg)(5 m/s)2 = 25 J
Potential Energy • An object with POTENTIAL ENERGY has the ability (or potential) to move or change • Sometimes called “energy of position” or “stored energy” • There are 3 types of potential energy: • Gravitational Potential Energy • Elastic Potential Energy • Chemical Potential Energy
Gravitational Potential Energy • Potential Energy due to an object’s position • Formula: PE = mgh height (in meters) mass (in kg) acceleration of gravity (9.8 m/s2)
Gravitational Potential Energy • The person has more potential energy at the top of the stairs than at the bottom.
Gravitational Potential Energy Where does the egg have more potential energy? Why?
Gravitational Potential Energy • If your egg drop device has a mass of 2 kg, how much potential energy does it hold at a height of 10 meters? PE = ? m = 2 kg g = 9.8 m/s2 h = 10 m PE = mgh PE = (2 kg)(9.8 m/s2)(10 m) = 196 J
Elastic Potential Energy • Potential energy due compression or expansion of an elastic object
Chemical Potential Energy • Potential energy stored within the chemical bonds of an object
Kinetic or Potential? Every pair will receive a whiteboard and a marker. I will put a picture up on the board. You will have 30 sec to decide whether the picture represents kinetic or potential energy. Do not put your board up until I say. Be prepared to defend your answer!
Graphic Organizer Summary Joules (J) PE= mgh Potential Kinetic Chemical Gravitational KE = ½ mv2 Elastic mass velocity mass position
Practice Problems • 10 min to complete the practice problems • Work together • Show all of your work!! • Raise your hand if you have a question
Exit Ticket • Complete the questions silently and independently • Hand it to me on your way out when the bell rings • Remember – I want to see your BEST work!