| 4月28日 第3節 教育研究所乙組 | 誠實是我們珍視的美德， 我們喜愛「拒絕作弊，堅守正直」的你！ |
| 科目： 物 理 | （共2頁 第1頁） |
| The following description is for the next three questions:
(15 points) |
|
| Consider a block of ice on a friction-free frozen lake. Suppose a continuous force acts on the block horizontally. Of course, this causes the block to get a move on, to accelerate. After the force has acted for some time the speed of the block has increased a certain amount. | |
| 1. | Now if the force and mass of the block are unchanged but the time the
force acts is doubled, then the speed will be (A) unchanged. (B) doubled. (C) tripled. (D) four-fold. (E) cut in half. |
| 2. | Next, if the force and action time are unchanged but the mass of the
block is doubled, then the speed will be (A) unchanged. (B) doubled. (C) cut in half. (D) four-fold. (E) cut to 1/4. |
| 3. | Finally, suppose the applied force, mass, and action time are all as
they were initially, but somehow the force of gravity is doubled-like
if the experiment were conducted on another planet. Then the increase
in speed will be (A) unchanged. (B) doubled. (C) cut in half. (D) four-fold. (E) cut to 1/4. |
| The following description is for the next three questions:
(15 points) |
|
| A thin plano-concave lens has an index of refraction of
1.25 and the radius of curvature for the concave surface is 10 cm. |
|
| 4. | When light is incident on the plane surface, what is the focal length
of the thin lens? (A) +40 cm. (B) +20 cm. (C) -20 cm. (D) -40 cm. (E) None of the above. |
| 5. | When light is incident on the concave surface, what is the focal length
of the thin lens? (A) +40 cm. (B) +20 cm. (C) -20 cm. (D) -40 cm. (E) None of the above. |
| 6. | If this lens is immersed in water, the lens becomes (A) converging with a longer focal length. (B) converging with a shorter focal length. (C) diverging with a longer focal length. (D) diverging with a shorter focal length. (E) converging when light is incident on the plane surface yet diverging when light is incident on the concave surface. |
| The following description is for the next three questions:
(15 points) |
|
A small spherical insulator of mass of 0.43 g and charge
+0.04 μC is hung by a thin string of negligible mass. A charge of -0.09
μC is held 0.01 m away from the sphere and directly to the right of it
so the string makes an angle θ with the vertical. 
|
|
| 7. | What is the angle θ? (A) 30°. (B) 37°. (C) 45°. (D) 53°. (E) 60°. |
| 8. | What is the total electrostatic potential energy of the two-charge system?
 |
| 9. | Where should a third charge of -13.00 μC be placed so that neither the
angle θ nor the locations of the two charges will be changed? (A) 4 cm from and to the left of the +0.04-μC charge. (B) 6 cm from and to the left of the +0.04-μC charge. (C) 4 cm from the +0.04-μC charge and 6 cm from the other charge. (D) 6 cm from the +0.04-μC charge and 4 cm from the other charge. (E) None of the above. |
| 10. | List all resources and their features that you know of and believe might
be helpful for physics teachers. (15 points) |
| 11. | Describe your most favorite physics demonstration with inexpensive
materials that are easy to obtain and construct. This demonstration must
be educational and easy to conduct in class. (20 points) |
| 12. | State your philosophy of physics teaching. Notice your audience whom
you (will) instruct or have taught. (20 points) |
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