DAY 62

Essential Question: How can I show that energy cannot be created or destroyed, but CAN be transported from one place to another, and CAN be transferred between systems?

#Goals: SWBAT...

1. Draw and explain a molecular model showing what happens to the skater’s molecules at the microscopic level as thermal energy increases, then relate this to what is happening at the macroscopic level of the skater on the ramp.

2. Differentiate between total energy and various forms of energy in a system. 

3. Explain how each model (bar graph and pie chart) shows the total energy of the system, and draw each model for a situation with a different amounts of initial energy. 

4. Describe energy changes in a system over time using both words and graphical representations.

Standards

That there is a single quantity called energy is due to the fact that a system’s total energy is conserved, even as, within the system, energy is continually transferred from one object to another and between its various possible forms. ((HS-PS3-1), (HS-PS3-2)

Conservation of energy means that the total change of energy in any system is always equal to the total energy transferred into or out of the system. (HS-PS3-1)

Energy cannot be created or destroyed, but it can be transported from one place to another and transferred between systems. (HS-PS3-1)

The availability of energy limits what can occur in any system. (HS-PS3-1)

Warm-Up (3min): Energy Skate Park 

Answer the Essential Question from above. Use complete sentences. You can use an example to describe how to show.

CLASSWORK

absent today? Here's the handout: https://drive.google.com/file/d/0B31ORq_bI3-VT1pYUzVFSkUxekJsY25rTm1qbVo5RUZxZDQw/view?usp=sharing

1. 061A: Review KE and PE Review

2. 062A: Energy Changes in the Skate Park System

1. Follow directions to complete pages 2-4

2. Observe the forms and quantities of energy in the system at different positions

3. Some key concepts to consider:

   1. Should total energy remain constant?

   2. How can you give the skater the highest initial energy?

   3. The total energy represents the sum of _______________________

      1. How is this represented on a pie chart?

      2. How is this represented on a bar graph?

4. Share out/Whole class discussion

5. LINK to Skate Park Simulator: http://phet.colorado.edu/sims/html/energy-skate-park-basics/latest/energy-skate-park-basics_en.html

3. 062C: Mathematical Model for Conservation of Energy - student handout pages 5

1. Begin section C by completing page 5. 

2. Share out/Whole class discussion

At Home Learning (HW) 

1. Complete the classwork from day 62. Need help? Video ---> https://youtu.be/lX2yTtsiE9k

2. Quiz Friday on Work, Kinetic Energy, and Potential Energy. Prepare by reviewing concepts and practice problems from Day 56 through now

3. Revise your It's All Uphill assignment, look for any quizzes to retake, check to make sure a retake is available, and if not, ask me via the Remind App to make a new version so you can retake quizzes before the break.

4. After today, 2 days until Thanksgiving break, and 13 days until the beginning of finals. 

I will have a final exam review for you this week. 

#Goals: SWBAT...

1. Write & understand the equations for Kinetic and Potential Energy

2. Set an appropriate reference (zero) line.

3. Solve KE and PE problems

***Warm up check for Day 56-64 (9 warm-ups total) will be Friday 11/16***

Warm-Up (4min): Review KE and PE from the learning at home videos

1. Write the equation for Potential Energy (PEg) 

2. If you're measuring the PEg of a basketball being thrown above the ground, which location of the reference (zero) line makes the most sense?

    i. setting the line at the ball's highest possible position?

    ii. setting the line at the ball's lowest possible position? 

    iii. setting the line at the average of the ball's lowest and highest positions? 

3. Write the equation for Kinetic Energy (KE).

4. If you double the velocity of an object, the KE value quadruples. If instead, you triple the velocity, what happens to the value of the KE? Hint: think about what the v2 part of the equation means....

5. Is PEg a vector or scalar? What about KE?

CLASSWORK

1. #062A: Potential Energy: Notes

• Definition: Potential energy is the stored energy of position possessed by an object.

• What does that mean? There is a direct relation between gravitational potential energy and the mass of an object. More massive objects have greater gravitational potential energy. There is also a direct relation between gravitational potential energy and the height of an object. The higher that an object is elevated, the greater the gravitational potential energy. 

• Equation:          PEg = mass • gravity • height 

•                   or...      PEg = m • g • h

• In the above equation, m represents the mass of the object, h represents the height of the object and grepresents the gravitational field strength (9.8 N/kg on Earth) - sometimes referred to as the acceleration of gravity

• Check for Understanding: If you double the height of an object, what happens to the PEg?

2. #062B: Kinetic Energy: Notes

• Definition: Kinetic energy is the energy of motion

  • The kinetic energy of an object is directly proportional to the square of its speed. 

  • That means that for a twofold increase in speed, the kinetic energy will increase by a factor of four. For a threefold increase in speed, the kinetic energy will increase by a factor of nine. And for a fourfold increase in speed, the kinetic energy will increase by a factor of __________. The kinetic energy is dependent upon the square of the speed.

• Equation: KE = 1/2 • m • v2

• where m = mass of object

• v = speed of object

  • You can often trade KE for PE, and vise versa. We'll learn more about that kind of Conservation of _________ tomorrow

3. #062C: PEg and KE Practice Problems

1. A cart is loaded with a brick and pulled at constant speed along an inclined plane to the height of a seat-top. If the mass of the