Transcript Strategies_for_teaching_AP_Physics_B

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 exam
ranges
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 skills
It helps give students and teachers a break
especially on high stress days such as testing or
tough topics.
Labs for AP Physics B
Zin activity with dimensional analysis
Task
Uniform motion with a battery-operated car
Exploratory Kinetic energy in linear collisions
Exploratory Energy conservation with projectiles -- task to hit a target
Exploratory
Exploratory Spring energy with a pop-up toy --- task to find spring constant
Task
Energy of a bouncing ball
Task
Exploratory Floating and Sinking -- Archimede's Principle
Exploratory Electrostatics -- Conduction and Induction
Exploratory
Task
Bull's eye -- Assymmetrical projectile task
Exploratory Millikan simulation
Task
Ohm's Law
Amusement Park Physics at Adventureland
Exploratory
Series circuits
Exploratory
Friction
Exploratory
Kilogrammy lab -- Static equilibrium task to find unknown mass
Task
Parallel circuits
Exploratory
Torque
Task
Series-parallel virtual circuit lab
Exploratory
Terminal velocity
Exploratory
Magnetic Fields
Exploratory
Newton's 2nd law -- Effect from changing mass
Exploratory
Electromagnetism
Exploratory
Newton's 2nd law -- Effect from changing net force
Exploratory
Speed of sound using resonance
Exploratory
Atwood machine -- task to find unknown mass
Task
Curved mirrors -- task to find radius of curvature
Task
Impulse and momentum -- with a popper toy
Exploratory
Refraction effects
Exploratory
Impulse and momentum -- task to protect an egg
Task
Index of Refraction of glass
Exploratory
Hooke's law
Exploratory
Index of Refraction of unknown liquid
Task
Simple Harmonic Motion with a spring
Exploratory
Lenses
Exploratory
Simple Harmonic Motion with a pendulum
Circular Motion
Exploratory Double lens system -- task to find a final image from two lenses
Exploratory Finding wavelengths of visible light using diffraction gratings
Conservation of momentum in linear collisions
Exploratory
Conservation of momentum in two-dimensional collisions
Exploratory
Falling objects and the acceleration of gravity
Motion on an inclined plane
Hole in One? -- Horizontal projectile task
Projectiles at angles
Pendulum I
Phootball physics and What's your trajectory?
Work
Exploratory
Task
Exploratory
Exploratory
Exploratory
Task
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?