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These fundamentals checks are just as appropriate for AP Physics C (mechanics) as for AP Physics 1. Those two courses cover the exact same topics! And, if you're going to be successful on the C exam, you need to first understand everything on the 1 exam.
I've been repeatedly asked about the viability of teaching a combined section of APC and AP1. That's totally doable... because I'd teach it as just AP Physics 1 until about March. Then, as the AP1 students do cumulative review for the exam, the APC students can do their review in the context of practicing calculational problems, and of learning some of the calculus techniques unique to the C exam.
My experience, and the physics education literature, all demonstrate clearly that it's straightforward for a students to use a strong conceptual foundation as a springboard for success in mathematical physics. But it's very difficult to go the other way around, for a student to use mathematical problem solving skills as a platform for developing strong conceptual understanding. Even though that seems counterintuitive to professional physicists.
Fundamentals Check #9:
81. I attach a 20 g mass to a spring, set the spring in harmonic motion, and measure its period. The mass is determined using period = 2πroot(m/k). Did I determine gravitational mass or inertial mass?
82. Define torque.
83. How do you determine an object's speed from a velocity-time graph?
84. A car moves east at 30 m/s. Ten seconds later, the car moves east at 10 m/s. What is the magnitude and direction of the car's acceleration?
85. Cart A, of mass 1 kg, moves left with speed 1 m/s. Cart B, of mass 1 kg, moves right with speed 1 m/s. What is the total kinetic energy of the two-cart system?
86. Cart A, of mass 1 kg, moves left with speed 1 m/s. What is the magnitude and direction of cart A's momentum?
87. A ball has 100 J of gravitational potential energy relative to the ground when it is dropped from rest from a high cliff. The ball has 60 J of kinetic energy right before hitting the ground. How much work was done by air resistance during the ball's fall?
88. A ball is launched vertically off of a table, 70 cm above the floor. The ball reaches a maximum height of 160 cm above the floor, then falls to the floor. What is the magnitude of the ball's displacement between the table and the floor?
89. What is the formula for rotational inertia of a point object?
90. About how much of a circle is a radian? (Your answer may not reference π).
Solutions to Fundamentals check 9:
ReplyDelete81. inertial. (The equation for the period of a spring does not involve gravitational field or the universal gravitation constant.)
82. force times lever arm.
83. look at the vertical axis.
84. 2 m/s/s, west. (Acceleration is the change in speed every second. The car changes speed by 20 m/s over 10 seconds, so that's a change of 2 m/s every 1 second. And when an object slows down, its acceleration is opposite the direction of motion.)
85. 1 J. (Kinetic energy does not have direction; so all kinetic energies add together. Each cart has 0.5 J of kinetic energy.)
86. 1 Ns, left. (Momentum is mv; the direction of momentum is the same as the direction of motion.)
87. 40 J. (The energy bar chart will show that 100 J of gravitational energy plus the work done by air resistance equals the 60 J of kinetic energy at the ground. Leaving 40 J of work done by air.)
88. 70 cm. (Displacement is the distance from the beginning to the end of a motion, without regard for what happens in between.)
89. MR^2.
90. about 1/6 of a circle, or about 60 degrees. (To two digits, that'd be 57 degrees.)