A major strategy to help students learn AP PHYSICS B

Do More Labs

Models for the AP B course

• 2nd year course -- double period every other day

• 1st year course – double period every other day

• 1st year course – double period every day

You don’t have to learn or teach the entire course to get a 5.

AP Grade 2009 examranges

Minimum percent for grade

5 112 - 180 62 %

4 85 - 111 47%

3 57 - 84 32%

2 40 - 56 22%

1 0 - 39 0%

Even a very good Regents student can get a 3 on the AP exam.

Covering the material doesn’t mean the students have learned it.

Why do more labs?

Students enjoy doing hands-on activities.Students are still basically doing physics problems and calculations.Students are learning other things besides physics e.g. how to use a clamp, compass, protractor, etc. TROUBLESHOOTING skillsIt helps give students and teachers a break especially on high stress days such as testing or tough topics.

Labs for AP Physics BZin activity with dimensional analysis TaskUniform motion with a battery-operated car ExploratoryFalling objects and the acceleration of gravity ExploratoryMotion on an inclined plane ExploratoryHole in One? -- Horizontal projectile task TaskProjectiles at angles ExploratoryPendulum I ExploratoryPhootball physics and What's your trajectory? ExploratoryBull's eye -- Assymmetrical projectile task TaskAmusement Park Physics at Adventureland ExploratoryFriction ExploratoryKilogrammy lab -- Static equilibrium task to find unknown mass TaskTorque TaskTerminal velocity ExploratoryNewton's 2nd law -- Effect from changing mass ExploratoryNewton's 2nd law -- Effect from changing net force ExploratoryAtwood machine -- task to find unknown mass TaskImpulse and momentum -- with a popper toy ExploratoryImpulse and momentum -- task to protect an egg TaskHooke's law ExploratorySimple Harmonic Motion with a spring ExploratorySimple Harmonic Motion with a pendulum ExploratoryCircular Motion ExploratoryConservation of momentum in linear collisions ExploratoryConservation of momentum in two-dimensional collisions Exploratory

Work Exploratory

Kinetic energy in linear collisions Exploratory

Energy conservation with projectiles -- task to hit a target Task

Spring energy with a pop-up toy --- task to find spring constant Task

Energy of a bouncing ball Exploratory

Floating and Sinking -- Archimede's Principle Exploratory

Electrostatics -- Conduction and Induction Exploratory

Millikan simulation Task

Ohm's Law Exploratory

Series circuits Exploratory

Parallel circuits Exploratory

Series-parallel virtual circuit lab Exploratory

Magnetic Fields Exploratory

Electromagnetism Exploratory

Speed of sound using resonance Exploratory

Curved mirrors -- task to find radius of curvature Task

Refraction effects Exploratory

Index of Refraction of glass Exploratory

Index of Refraction of unknown liquid Task

Lenses Exploratory

Double lens system -- task to find a final image from two lenses Task

Finding wavelengths of visible light using diffraction gratings Task

Lab: Newton’s 2nd Law – Part I Purpose: To verify that F net = ma.

Effect of a Changing Net Force

Procedure: Mass a cart. Attach the string to the cart and place several masses into the cart. Record the mass, in kilograms, of the entire system with the cart and its masses. Remove one of the smaller masses and attach it to the other end of the string. Keep all the other masses in the cart and place the cart on the board. Hang the small mass over the other end of the pulley. This hanging mass will provide the net force that will accelerate the system. Record the net force (in newtons). Make sure the string is taut between the cart and the hanging mass and release the cart from rest. Put the Smart Timer on acceleration mode with a linear pulley. To measure the acceleration, press the start button until the asterisk appears. Release the system from rest. Record the acceleration from the timer. Repeat three more times and get an accurate average value, converting it to m/s2, for the acceleration.

Repeat this procedure 8 times by changing the net force that accelerates the system without changing the mass of the system. Do this by exchanging masses within the cart. Do not use over 100 grams to accelerate the system for the air track or 150 grams for the metal track.

Construct a chart that you will show all the data you recorded in an organized manner.

Construct a graph of the net force (on the y-axis) versus the acceleration (on the x-axis). [Remember that the net

force is equal to the hanging weight for each trial.] Draw a line of best fit. Conclusion Questions: 1. Draw a freebody diagram of the forces acting on the cart or glider as it moves. Label the forces.

2. Based on your graph, what is the relationship between force and acceleration? 3. Calculate the slope of your graph. Be sure to show formula and substitution with units. 4. The slope of your graph should be equivalent to the mass of the system. Determine the percent error between the actual mass and the value you just calculated from the slope. 5. Explain why the slope of your graph should be equal to the mass of the system. 6. Choose the last trial to find the net force using Fnet= ma. This net force should be equal to the hanging weight. Calculate the percent error between the net force and hanging weight. 7. Give a reason as to why your calculated net force will not equal the actual hanging weight.

   

Part II: Determining the target position for a given angle [10 pts] and its corresponding hang-time [5 pts]. Return your marble to your teacher. You will be given a launch angle for your launcher. You are to calculate how long the projectile will be in the air and where the target sheet should be when the projectile lands. Show your work below. angle of release = __________ When you are ready, tape your target sheet to the target pad. Place a carbon sheet face down over the target sheet. Release the marble 3 times at the specified angle. The "best" two marks will be counted for your grade in this section. Your closest time value will be counted for the hang-time section. calculated target position location (x) = ________________ calculated hang-time = __________ --------------------------------------------------------------------------------------------------------------------------------- official use only target position points = ____________ actual hang-time = _________ percent error = ____________

If students only remember 10% of your class, what 10% do you want

them to remember?