AP Physics:Newton's Laws in Three Pictures

Learning Objectives

Students will be able to recognize Newton's Laws of Motion in ordinary situations.

Assessment Type
This activity can be used as a formative assessment to check student's conceptual understanding of Newton's Laws of Motion.

Assignment Details
Ask students to go around the school, looking for examples of Newton's Laws of Motion. When they find a situation that illustrates one of Newton's Laws, students should take a photograph using a digital camera (cell phones would work fine).

After returning to the classroom, students should write a brief description of how each image illustrates one of Newton's Laws. For example, a student description for the images above may look like:

1st Law: A stapler is sitting on a desk illustrating that objects at rest will stay at rest.

2nd Law: When pushing someone on a swing, a greater force must be applied to someone with a greater mass in order to achieve the same acceleration.

3rd Law: When the hamster runs in his wheel, there are two forces between his feet and the wheel -- one pushing his feet forward and the other pushing the wheel backward.

Instructor's Notes
Students can use one of several free online tools to create an animated .gif of their images (as above). The student's work can then be added to a class website, showing all the different ways Newton's Laws can be found in everyday life.

This same activity can be used to check student understanding for a wide variety of conceptual topics in AP Physics. For example, conservation of momentum, oscillations, refraction, and resonance would all make for an interesting series of photos.

As a formative assessment, this activity could be graded on a completion basis. Rewards, such as placing the best examples on the class website, could be used to motivate students toward excellent work.

AP Physics:The Kinematics of Plants vs Zombies

Learning Objectives

• Students will be able to apply equations of motion to the video game, Plants vs Zombies

Assessment Type
This lab activity asks students to use video analysis software to address several questions related to the motion of zombies in the popular video game, Plants vs Zombies. This activity could be used as a formative or summative assessment of students' knowledge related to constant-velocity motion. It could also be used as an introductory review activity for AP students prior to starting the first unit.

Assignment Details

• Before beginning this activity, students should download and install the required software:
• Tracker: This is a powerful open-source video analysis tool for physics teachers. It makes a great free alternative if you do not have Vernier's LoggerPro software, which can also perform the same video analysis.
• Plants vs Zombies: While the video snippets needed for this activity can be downloaded below. It will be helpful for students to have some experience with the actual game. It can be played in the web browser or downloaded as a free demo.
• The activity can be presented to students as a series of questions. Students are directed to collect data that clearly and convincingly answers the following questions.
• Question 1: Does the pea shooter slow down the zombies?
• Question 2: At what position and time will the javelin-carrying zombie pass the cone-wearing zombie?
• Question 3: By how much does the frozen pea shooter slow down the zombie?
• Students will create a lab report or a brief video that presents their data, describes their analysis, and explains their conclusion.

Instructor's Notes

• If you have screen recording software available, you can ask that students make their own videos for analysis, otherwise students can use the following videos to address each of the questions.
• Question 1 Video
• Question 2 Video
• Question 3 Video
• Students could be assigned to answer all three of the questions or given the option of choosing just one question to answer. Question 2 is the most open ended and would require students to make careful choices regarding their frame of reference for measurements.
• Students can compare their prediction in Question 2 to this video, which shows the javelin-carrying zombie passing the cone-wearing zombie.
• The following could be used as a simple rubric for evaluating this student activity:
  (10 pts) - Clear and convincing conclusions are drawn that are consistent with the data
  (5 pts) - Data analysis is correct and appropriate for the question being addressed
  (5 pts) - The data was collected accurately and illustrates the motion shown in the video.

AP Physics:The Physics of Osmos

Learning Objectives

• Students will be able to recognize and explain physics concepts in novel situations.

Assessment Type
This activity asks students to recognize physics concepts within the video game Osmos. Students are then asked to use the video game to demonstrate and explain the concept that they have identified. This activity can be used as a formative assessment of student understanding or as a summative assessment after a comprehensive introduction to kinematics or momentum.

Assignment Details

• Students begin by watching the following YouTube video: http://www.youtube.com/watch?v=FWlP9ix3ukg

• Students should then download and install the free demo of Osmos, which is available on a variety of platforms including Windows and Mac computers (http://www.hemispheregames.com/osmos/). Osmos is also available for purchase through the iTunes App Store for iPad, iPhone, and iPod Touch.
• Students will experiment with the game, looking for physics concepts that could be demonstrated using the video game as their laboratory.
• Using screen capture images or free video screen capture software (such as Jing: http://www.techsmith.com/jing/), students can create their own video demonstration and post it to YouTube as a response to the original "Physics of Osmos" video.

Instructor's Notes

• There are a wide variety of concepts that can be demonstrated with this game. If students' need help identifying possible topics, direct them toward: Newton's 1st, 2nd, or 3rd law, elastic collisions, inelastic collisions, conservation of momentum, or rocket propulsion.
• Using later levels of the game, students can also explore gravitation and orbits, these levels could be used as a demonstration of Kepler's Laws, uniform circular motion, or simple harmonic motion.
• As a possible follow-up to this activity, include screenshots from Osmos on an end-of-unit test or final exam. Ask students to solve a problem involving the glowing orbs or to explain a concept in the context of the game.
• The following could be used as a simple rubric for evaluating this student project:
  (10 pts) - Physics concept is named and explained in the video
  (5 pts) - Concept is convincingly demonstrated using the game
  (3 pts) - Video is clear, concise, and easily understandable
  (2 pts) - Student showed creativity or insight in their demonstration

AP Physics:Air and Fluid Pressure Activity

Learning Objectives
From Chapter 7 of AP Physics B

• Understand and apply the relationship between pressure and depth in a fluid.

Assessment Type
This activity challenges students to explain very familiar phenomena using the concept of fluid pressure. In the process, even advanced students will have their misconceptions about pressure revealed. This activity can be used as a formative assessment of conceptual understanding or even as "practicum" component on a test or quiz.

Assignment Details

1. Provide students with a few basic supplies: 5-10 plastic straws, a small cup filled with water.
2. Ask students to perform the following three experiments and record their observations as well as a detailed explanation using the concept of pressure.
   
   Experiment 1: With the straw only in air, place a finger over the top of the straw, closing the top end off. Put the bottom end of the straw into the cup of water and record your observations and explanation.
   
   Experiment 2: With the straw open on both ends, put the straw halfway submerged into the water. Place a finger over the top of the straw, closing the top end off. With a finger still over the top, remove the straw from the water and record your observations and explanation.
   
   Experiment 3: Make an extra long straw by connecting two straws together in a chain. Place the straw in a cup of water and attempt to move the water up the straw to your mouth with a single long and constant draw. If you are successful in getting water all the way to the top, then add another straw to your chain and try again. Find the highest straw length where it is no longer possible to move the water to your mouth with a single constant draw. Record your observations and explanation.
   
3. Allow the students to experiment, providing as much autonomy as possible and trying not to influence their observations or explanations.
4. After students have completed the experiments, ask them to share their observations by facilitating a class discussion. Go through each experiment one-by-one, with students sharing their observations and then discussing their explanations of the results.
5. Use leading questions to correct misconceptions and always return to the experiment when there is disagreement about what actually happened.
6. As a final test of their understanding ask students if there is an absolute limit to the height of a usable straw (even if a machine used the straw instead of a person). If so, what would cause this limitation? and how high would the maximum height be?

Instructor's Notes

• Each of these experiments demonstrates the strong influence of air pressure. Students will be tempted to explain the experiments in terms of "vacuums" and "suction." Feel free to forbid the use of these two terms at the start of the lesson.
• When "sucking" water up the straw, be sure that students keep the straws vertical, so that they do in fact reach a limit. Students will reach various limiting heights with their straws. This height is limited by the degree to which the pressure in the straw is lowered below atmospheric pressure. In some sense, this height can be used as a measure of lung strength.
• The absolute limiting height up to which a straw can be used is determined by atmospheric pressure. The pressure caused by the weight of the column of air above the surface of the water can push the water up the straw until the weight of the fluid in the straw matches that of the column of air. Estimates on a numerical value for this height can be performed using the densities of air and water as well as the approximate column height of the atmosphere.

AP Physics:Free-Fall Motion Inquiry Activity

Learning Objectives
• Understand and apply the principle of free-fall motion in a uniform gravitational field.

Assessment Type
This inquiry activity is a wonderful launch point for a discussion on free-fall motion and particularly the non-negligible role that air resistance play in free-fall acceleration. The activity can also be used as a formative assessment of students' abilities to design an experiment, generate and test a hypothesis, and make careful observations.

Assignment Details

1. Provide students with just a few basic supplies: manilla folders, empty film canisters, and pennies.
2. Ask students to collect data using these simple tools to answer the following two questions:
   a) Does mass impact the rate at which objects fall?
   b) Does shape impact the rate at which objects fall?
3. Allow students to experiment, provide as much autonomy as possible and try to accommodate student requests for other resources (rulers, timers, tape, etc) as they carry out their experiments.
4. After students have experimented for some time, ask them to share their conclusions by facilitating a class discussion. Any statement made by a student or group should be confirmed by a simple experiment shown to the class.
5. Through the process of testing one another's conclusions, work with the students to generate a statement describing the conditions under which mass and shape seem to impact the rate at which objects fall, being sure that everyone agrees to the language used.
6. As a final test of their conclusions, choose two new objects that the students have not experimented with -- say a styrofoam cup and a plastic cup. Ask the students to discuss which would hit the ground first when dropped from the same height, and under what conditions the opposite result could be achieved.

Instructor's Notes

• Physics instructors often teach students that mass does not impact an object's free-fall rate. While this is true in the absence of air resistance, it is not true under normal circumstances. This activity can be used to demonstrate why Galileo's understanding of free-fall motion took thousands of years to emerge.
• The joy and challenge of this activity is the open nature of the experimentation. Allow students to pursue experimental dead ends and even to make incorrect conclusions from their experiments. Through the class discussion, students will confront their misconceptions and be forced to reconcile them with the experimental evidence.
• This activity can be used as an introduction to free-fall motion, before the simplifying assumption of ignoring air resistance is made. It could also be used after free-fall motion has been studied in detail and as an introduction to friction and/or terminal velocity.