23 April 2024

Fundamentals checks for AP Physics *2*

Last year I wrote a bunch of fundamentals checks in preparation for the AP physics 1 or C-mechanics exams.  This year, I'm teaching a physics 2 section.  So, I'm writing daily quizzes for P2 now!  I'll post the quizzes here, then follow up a couple of days later with the answers in the comments.


Quiz 1:

1.       A substance has index of refraction 1.5.  What is (or how do I figure out) the speed of light in this substance?

2.       Write the equation relating focal length, image distance, and object distance for a mirror.

3.       Write the equation for the energy carried by a photon.

4.       Under what conditions is the image distance di positive, and under what conditions is it negative?

5.       The diagram shows light hitting a mirror.  What is the angle of incidence as the light hits the mirror?






6.       A resistor is connected to a battery, and the current in the circuit is measured.  The voltage of the battery is increased, and the current is measured again.  Which Ohm’s Law variable(s) remain unchanged after the voltage is increased?

7.       Under what conditions is the electric field given by the equation E = kQ/d2?

8.       One mole of monotomic ideal gas begins at pressure P1 and volume V1­.  Next, the pressure is increased to P2 without changing the volume.  Write an expression (including a + or – sign) for the work done on the gas.

 9.       Write the equation for the capacitance of a parallel plate capacitor.

 10.   A photon initially has wavelength 500 nm.  The photon collides with a free electron which was initially at rest, giving the electron 3.0 eV of kinetic energy.  The photon bounces back opposite the direction it was initially moving.  What is the speed of the reflected photon?


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1 comment:

  1. Greg JacobsApril 25, 2024 at 11:12 AM

    Greg's answers to P2 fundamentals quiz #1:

    1. Use n=c/v, and solve for v where c = 300,000,000 m/s. (This gives 200,000,000 m/s)
    2. 1/f = 1/di + 1/do
    3. E = hc/[lambda], or E = hf.
    4. image distance is positive for real (or inverted) images, negative for virtual (or upright). [There are more complicated ways to remember this based on whether the image is in front of or behind the mirror/lens, but the first sentence here is easiest.]
    5. 30 degrees. [Angle of incidence is measured from the NORMAL to the incident ray.]
    6. R - resistance is a property of a resistor, and I didn't change the resistors in the circuit.
    7. When the electric field is produced by a point charge [i.e. a small charged object].
    8. W = 0, i.e. no sign. [Work is the area under a PV graph, and without a volume change there's no area]
    9. C = (e0)A/d. [Or, keA/d for a parallel plate capacitor with a dielectric material inside. Here, e means Greek letter epsilon, and k means Greek letter kappa.]
    10. c. [A photon is a light particle, so it always moves at speed c = 300,000,000 m/s]

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