Physics Concepts Broken into 2 Categories 1 Forces

Physics Concepts Broken into 2 Categories 1. Forces and Motion 2. Energy Sources and Transformations

Forces and Motion • Forces (a push or a pull) cause motion – Gravity: the pull from a planet’s or star’s mass – Magnetic: push or pull from magnetic poles – Electric: push or pull from charged particles

Forces and Motion • Motion is Measured in… – Distance – Time – Speed – Acceleration

Newton’s Laws of Motion 1 – Objects in motion will remain in motion. Objects at rest will remain at rest. 2 – Force = Mass x Acceleration 3 – For every action force there is an equal and opposite reaction force.

Energy Sources and Transformations • Energy cannot be created or destroyed, only transformed • Energy Forms – Light – Heat – Chemical – Electrical – Mechanical

Light and Heat Light – Part of the Electro-Magnetic Spectrum. Transmitted as a wave/particle through space. Light from the sun enables life on earth. Heat – The energy in transit between objects of differing Temperature Associated with the speed of atoms/molecules that make up matter. Transmitted by conduction, convection, and/or radiation.

Common Example Energy Transformations • Light energy from the Sun is transformed into Chemical energy by plants. That Chemical energy is transformed to Mechanical energy by humans. • Heat energy in a Power Plant is converted into Mechanical energy. The Mechanical energy is transformed into Electrical energy by the turbine. Electrical energy is transformed into Light energy by a light bulb, or Heat energy by a toaster in your home.

1) During which of the following processes is there a decrease in the heat content of the form of water indicated? a. Ice as it forms on a lake b. Water droplets as they fall to the ground c. Water as it evaporates from a pond d. Snow as it melts on a mountainside 2) When the car accelerates from a standing start, the crash test dummy appears to be pressed backward into the seat cushions. Which of the following best explains why this happens? a. The crash test dummy gets lighter as the car accelerates. b. The car is moving forward faster than the crash test dummy. c. There is no reaction to the force of the car taking off. d. Gravity is pulling the crash test dummy in the direction the car is moving. 3) The highest concentration of life exists in the top 200 meters of ocean water. The most important factor that influences this concentration of life is the… a. amount of gases at the surface. b. amount of nutrients in the water. c. large number of predators at lower depths. d. amount of sunlight.

Recreational Center Pool A local recreation center has received funding to build a swimming pool. After construction, the center will be responsible for all costs associated with pool operation. As a result, the center must consider a variety of design options, including pool size, location and heating. 1. What happens to water molecules in a pool as they absorb energy? f. The molecules occupy less volume. g. The molecules begin to move more slowly. h. The kinetic energy of the atoms decreases. j. The rate of collision between molecules increases. 2. Prior to pool construction, engineers use computer models to compare which of several pool designs require the least amount of energy to be heated. What is the dependent variable in the computer models? a. pool size b. pool shape c. pool location d. pool temperature

Recreation Center Pool (continued) 3. Where should hot water enter the pool to better heat the water? f. A g. B h. C j. D

4. Each diagram shows two pith balls (foam balls coated with aluminum) hanging from strings. A pith ball can be given a positive (+) or a negative (-) electrical charge. Which of the following diagrams shows a correct way in which the charged balls will be attracted to or repelled by each other? A B C D

5. If three batteries are connected in series to the circuit, which of these shows the proper connection?

Constructed Response Solar Cooker Investigation A student hypothesized that container size will affect the performance of solar cookers in heating water. The student wrote and performed the following procedure to support her claim. Procedure: 1. Line three identical cardboard boxes with aluminum foil to use as solar cookers. 2. Place the solar cookers outside in direct sunlight. 3. Place a large glass container of water in the center of the first box. 4. Record the initial temperature of the water. 5. Allow the container to sit in the sun for 2 hours, and then check and record the final temperature of the water. 6. Place a medium-sized glass container of water in the center of the second box. 7. Repeat steps 4 and 5. 8. Place a small-sized glass container of water in the center of the last box. 9. Repeat steps 4 and 5.

Solar Cooker (Continued) The chart below shows the student’s data. Solar Cooker Data Temperature (°C) Container Initial Final Large 39 48 Medium 39 49 Small 39 49 a) Draw a conclusion regarding container size and the effectiveness of solar cookers in heating water, based on the student’s results. b) Describe two ways the student could have improved her experimental design and/or the validity of her results.

Multiple Choice Answers (Physics Questions) 1. 2. 3. 4. 5. j d j b b

Multiple Choice Strategies • Read – – Read the entire question carefully before you look at the answer. Don't read too much into a question. Circle or underline important words. Come up with the answer in your head before looking at the possible answers. • Analyze – – – Read all the choices before choosing your answer. Eliminate answers you know aren't right. For a graph or picture, determine the conclusion. Look for two answer choices that are opposites. Look for hints about the correct answer choice in other items on the test. Look for answer choices that contain language used by your teacher or found in your textbooks.

Multiple Choice Strategies • Choose – Always take an educated guess and select an answer. – Don't keep on changing your answer. – Never leave a question unanswered! • Guess (if you have no other option) – A positive choice is more likely to be true than a negative one. – Many times, the correct answer is the choice with the most information. – Don’t choose "None of the above" if you are certain one of the statements is true. – Choose "All of the above" only if you are certain that at least two answers are correct.

Constructed Response Strategies • Read – Read the entire question carefully. • Prepare – Before the test, know how your response will be scored. – Outline your response in the margin. • Answer – – – Restate the question to begin your sentence. Answer all parts of the question asked. Support your reasoning with detail. Write legibly. Do not skip any questions.

GENERAL TEST TAKING TIPS • Get a good night’s rest before the exam day. Also be sure to eat before the test to keep your energy up. • Dress in layers. Make sure you will not be bothered by an exam room that is warmer or cooler than normal. • Go to the bathroom before you enter the exam room. You don’t want to spend any time worrying about your bodily needs during the test. • Know the format of the test ahead of time. This includes the types of questions that will be on the test as well as how much time is allowed for each section. • When you first receive the test, do a quick survey of the entire test so that you know how to efficiently budget your time. • Manage your time wisely. Do not get stuck on a single question for too long. Move on to questions you can answer, and if time allows, return to the ones you skipped. Whatever the case may be, never leave a question blank. There is no penalty for guessing on the CAPT exam. • Keep a positive attitude throughout the whole test and try to stay relaxed. If you start to feel nervous or anxious, take a few deep breaths to relax. • If you have time left when you are finished, look over you test. Make sure you have answered all the questions. Watch out for careless mistakes and proofread your constructed response questions.