==2004-2005 P.O.D.s== ==PSLG== -- 15 DEC 2004 Q. Draw a lemon wet cell battery. Label the parts of the battery. A. Container (lemon peel); electrolyte (lemon juice, acetic acid); electrodes (different substances). -- 16 DEC 2004 Q. You are designing an electric battery. Why is it important to use electrodes made of different substances (elements or compounds)? A. ? ==2005-2006 P.O.D.s== ==PSLG== 22-23 MAR 2006 Q. Give an EXAMPLE of the following energy transformations: 1) nuclear to radiant to chemical 2) nuclear to radiant to chemical to electrical A. 1) nuclear fusion --> sunlight --> photosynthesis in plants 2) nuclear fusion --> sunlight --> photosynthesis in plants/lemon tree --> lemon chemical wet cell (battery) -- 27 MAR 2006 Q. Draw a lemon chemical wet cell. Label the essential parts of the lemon chemical wet cell. A. Container (lemon peel); electrolyte (lemon juice, citric acid); electrodes (different substances); conducting pathway (wire) closes the circuit. Q. You are designing an electric battery. Why is it important to use electrodes made of different substances (elements or compounds)? A. If the electrodes are the same, then there is no potential difference (voltage). -- 31 MAR 2006 Q. [write on blackboard...] Answer Ques. 3 shown on-screen (to left). [VA SOLs, Fixed Set No. 5, Ques. #3] Which of the following orientations of magnets would result in the _greatest_ attraction between the two magnets? A. F [A] Q. At which point (1-4) would the magnetic field be strongest? [2341] A. 1 -- 05-06 APR 2006 Prerequisite Info: Ohm's Law: I = V/r Where: I = current (amperage), amps (A) V = voltage r = resistance Q. Given a constant _voltage_, what is the mathematical relationship between _resistance_ & _current_? Q. Apply what you know (above) to explain what happens when you add more lights to a series circuit. -- [provide handout, PODs_re-Series-Parallel-Circuit.doc] Q. Series Circuit Given the positive & negative terminals on 9V battery, label the (+) and (-) terminals on the light bulb fixtures. A. connect unlike terminals (+,-,+,-, etc.) Q. Parallel Circuit "Rewire" the series of light fixtures so they are wired in parallel. Q. GWTF, Part 2 - Why isn't there a one-bulb parallel circuit? A. If there's only one bulb in the circuit, then it's a SERIES circuit! -- 21 APR 2006 [Show graphic featuring 5 crests w/in a 10 sec. bracket.] Q. What is the frequency of the wave shown above-left? A. 4 wavelengths/10 sec. = 0.4 waves/sec or Hz Note: Many students count number of crests, not number of wavelengths, resulting in the wrong answer. -- 24 APR 2006 [Show diagram of a transverse wave.] Q. What type of wave is shown? A. transverse Q. Label the parts of a wave: (1)rest position; (2)crest; (3)trough; (4)wavelength; (5)amplitude. -- 26 APR 2006 Q. What is the energy transformation that results in the transfer of energy from the Sun to the Earth? [Note: The "energy chain" has two (2) links.] A. nuclear energy (fusion) --> radiant energy -- 01 MAY 2006 [throw-back PODs] Q. What is the device inside the DuraPRO(R) flashlight (Costco) that makes it battery-free? A. a generator and a long-life rechargeable battery Q. Make an "energy chain" that shows the three (3) energy transformations. A. chemical --> mechanical --> electrical --> radiant chemical energy --> mechanical energy (kinetic) --> electrical energy --> radiant energy ==2006-2007 P.O.D.s== ==PSLG== -- 16 JAN 2007 Q. All forms of energy can be classified as either potential- or kinetic energy; classify the six (6) forms of energy listed in PB-10-LR accordingly. A. Potential: mechanical; chemical; nuclear Kinetic: mechanical; electric; radiant; thermal -- 24 JAN 2007 Q. Draw (hah!) and label the essential parts of a lemon wet cell. A. container (lemon peel); electrolyte (lemon juice, citric acid); electrode pair (e.g., Mg/C); conducting pathway (copper wires). -- 29 JAN 2007 Q. [Use words & arrows to] Make an "energy chain" that shows the energy transformations that occurred when the lemon wet cell was connected to the following low-power electronic devices: LED; buzzer. A1. LED: chemical (potential) --> electrical --> radiant A2. buzzer: chemical (potential) --> electrical --> mechanical (kinetic) "Note: Sound is mechanical energy because of the vibrating (moving) molecules creating the sound." PB1LR -- 12 FEB 2007 Q. Why is there no such thing as a one-bulb parallel circuit? A. Because the only way to wire a one-bulb circuit is in series. -- 20 FEB 2007 Q. A string of 20 Christmas tree lights is plugged in to a 120 V 15 A AC electrical outlet. If the lights are wired in series, then what is the voltage and amperage (current) for each individual light bulb? A. Voltage = 120V/20 = 6V; Amperage = 15A AC -- 28 FEB 2007 Q. Otis Elevators (manufactured by United Technologies) regenerates electricity for the buildings they serve. Explain how the system could work. Use the words "motor" and "generator" in your answer. A. Answers will vary; should feature the words "motor" and "generator" -- 05 MAR 2006 Q. In the movie, "Star Wars," we hear sound effects when the "Death Star" explodes (near the end of the movie). Why is this unrealistic? A. "There is no sound in space because there are no molecules there to transmit the [longitudinal] sound waves." http://www.srh.noaa.gov/srh/jetstream/remote/remote_intro.htm