DAY 63

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. Build , explain, and justify (with the sim) equations for total energy, and conservation of energy.

2. Draw scaled graphical models of energy for an object at a specific position using your energy equations.

3. Write equations for the total energy of an object at a specific position using scaled graphical models.

4. Use your energy model and equation to solve energy related problems.

5. Evaluate claims regarding roller coaster designs using evidence and reasoning from your energy model and the sim to support your conclusion.

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 

Use your classwork handout from yesterday

1. Based on your observations of total energy at different times and positions, write an equation to show the relationship between the total energy at A and at C. Use the diagram in #7, page 4

2. Use your observations about the relationship between total energy and the different forms of energy (KE, PE, ThE) to build a general equation for the total energy (Etot) in the system. 

CLASSWORK

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

1. #063A: Mathematical Model for Conservation of Energy - student handout pages 5 - 7

1. Complete section C

2. For page 7, The left 4 columns should all read "...at A". For example, the first column should read Eat A

   1. Share out/Whole class discussion

2. #063B: Using Conservation of Energy to Solve Real-World Problems - student handout pages 8-9

1. Complete section D

2. If you can't see part of question #2, here's the text: 

   1. 1. "An engineering student designed a loop for a roller coaster (see image on right), but did not factor in the effect of friction when calculating the measurements for the design.  What changes could be made to the design to ensure that the riders will go fast enough to make it around the loop? Justify your reasoning with evidence from the simulation or the equations."

• 1. Share out/Whole class discussion

At Home Learning (HW) 

1. Complete the classwork from day 62 and 63, due Friday 

2. Quiz Friday on Work, Kinetic Energy, and Potential Energy. Prepare by reviewing concepts and practice problems from Day 57 through now

2. 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.

3. After today, 1 day until Thanksgiving break, and 12 days until the beginning of finals. 

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

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

Warm-Up (3min): Energy Skate Park Introduction  

Click on the following link: http://phet.colorado.edu/sims/html/energy-skate-park-basics/latest/energy-skate-park-basics_en.html

Explore the simulation, and answer the questions below.

1. What can be done with the skater?

2. What tools do you have available?

3. What is the difference between the three screens (tabs at bottom)?

CLASSWORK

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

1. #063A: What's the Connection Between Friction and Thermal Energy?

1. Work in pairs

2. When you rub your hands together, describe what is happening (in terms of energy)? Where does the energy come from? How is friction involved?

3. What happens to the objects/molecules in a system when energy is converted to Thermal Energy? 

4. Friction Simulation: http://phet.colorado.edu/sims/html/friction/latest/friction_en.html

5. Follow the directions on page 1, and fill in the microscopic and macroscopic models.

   1. some microscopic concepts to consider: speed of individual molecules, size of molecules, temperature of molecules

   2. some macroscopic concepts to consider: how energy changes form, how heat is released, why the skater doesn't return to the same height on the ramp

6. Share out/Whole class discussion

2. #063B: Energy Changes in the Skate Park System

1. Work in pairs

2. Follow directions to complete pages 2-4 

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

4. 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?

5. Share out/Whole class discussion

At Home Learning (HW) 

1. Complete today's classwork

2. #063C: KE and PE Review

• answer the questions on pages 12-26. Skip page 19

• Since the question numbers are all over the place, use the following numbering system to record your answers.

  • Number each question based on the page number. Your paper should look like this:

  • 12: answer

  • 13: answer

  • 14: answer

  • 15: answer

  • 16: answer

  • 17: answer

  • 18: answer

  • (skip 19)

  • 20: answer

  • 21: answer

  • 22: answer

  • 23: answer

  • 24: answer

  • 25: answer

  • 26: answer

• Link to assignment: https://drive.google.com/file/d/1lHhrljJHfpNihOlfHYSkKF2HgULZd7L_/view?usp=sharing

*After some deep introspection, I decided that the Mass on a Spring Interactive assignment will now be extra credit. Turn it in by Thursday for some bonus lab points*

Unit Goals: What is a wave? How do they act? How are do waves differ?

Goals: SWBAT...

1. Define Amplitude & Wavelength

2. Find the Compression and Rarefaction zones on a longitudinal wave

3. Use Period and Frequency correctly to solve problems

Warm-Up (5min): 

1. Sketch the image. From where to where could you measure the wavelength? (hint, there are at least 4 answers)

CLASSWORK

1. #063A: Wave Components

    Transverse Waves (like in the warm up)

    a. Amplitude: distance from rest to crest

    b. Wavelength: length of one complete wave cycle (peak to peak, or trough to trough)

    Longitudinal Waves

    a. Compressions: where the waves are tightly packed (or compressed)

    b. Rarefactions: where the wave are spread apart (or rare)

    c. From where to where could you measure wavelength in the longitudinal wave above?

    Check Your Understanding

    Consider the diagram below in order to answer questions #1-2.

1. The wavelength of the wave in the diagram above is given by letter ______.

2. The amplitude of the wave in the diagram above is given by letter _____.

3. Indicate the interval that represents one full wavelength.

a. A to C

b. B to D

c. A to G

d. C to G

#063B: Frequency & Period

    a. if I say, "How frequently do you mow the lawn during the summer months?" what I'm really saying is, ____ _____ do you mow the lawn  

    b. TERM: Frequency

    DEFINITION: In mathematical terms, the frequency is the number of complete vibrational cycles of a medium per a given amount of time.

    UNITS: cycles/second, waves/second, vibrations/second, or something/second    Hz is the most common unit, which is called Hertz, and means cycles/second

    SYMBOL: f (for frequency)

    c. TERM: Period

    DEFINITION: The time it takes to complete one cycle (ex: time it takes for one wave to go by, time for one class from start to finish)

    UNITS: any time unit, but usually 

    SYMBOL: T (For time, but not little t, cause that's also time. Easy, right?)

    d. How Are They Related?

    Frequency is the cycles/second. Period is the seconds/cycle. Is there are relationship here? Could you come up with an equation?

063C: Practice Problems:

1. A wave is introduced into a thin wire held tight at each end. It has an amplitude of 3.8 cm, a frequency of 51.2 Hz and a distance from a crest to the neighboring trough of 12.8 cm. Determine the period of such a wave.

2. Frieda the fly flaps its wings back and forth 121 times each second. The period of the wing flapping is ____ sec.

3. A tennis coach paces back and forth along the sideline 10 times in 2 minutes. The frequency of her pacing is ________ Hz.

4. Non-digital clocks (which are becoming more rare) have a second hand that rotates around in a regular and repeating fashion. The frequency of rotation of a second hand on a clock is _______ Hz.

5. Olive Udadi accompanies her father to the park for an afternoon of fun. While there, she hops on the swing and begins a motion characterized by a complete back-and-forth cycle every 2 seconds. The frequency of swing is _________.

6. In problem #5, the period of swing is __________.

7. A period of 5.0 seconds corresponds to a frequency of ________ Hertz.

8. A common physics lab involves the study of the oscillations of a pendulum. If a pendulum makes 33 complete back-and-forth cycles of vibration in 11 seconds, then its period is ______.

9. A child in a swing makes one complete back and forth motion in 3.2 seconds. This statement provides information about the child's

a. speed

b. frequency

c. period

10. The period of the sound wave produced by a 440 Hertz tuning fork is ___________.

11. As the frequency of a wave increases, the period of the wave ___________.

a. decreases

b. increases

c. remains the same

Stuck? Answers are here at the bottom of the page: LINK

At Home Learning (HW) 

1. Complete #63C