107年 - 107 台灣聯合大學系統_學士班轉學考試_A3/A6/A7：普通物理#99865

1. Consider a one-dimensional system with potential energy plotted below. Whichx-u diagram correctly describes a particle with energy E₁ and another particle with energy E₂? (A)(B)(C)(D) (E)none of the above

2. A mass m is attached to a spring with spring constant k (the other end of the spring is Exed). The mass of the spring is negligible. When the mass moves at velocity v, there is a drag force -bu acting on the mass.
Which figure describes the displacement x of the mass as a function of time for some initial condition under the condition that the oscillator is overdamped?(A)(B)(C)(D)(E) none of the above

3. Consider an extra external force cosωt acting on the mass of a damped oscillator. The phenomenon "resonance" can be seen by varying ω on what kind of oscillator? (A)underdamped,(B)overdamped, (C)both kinds, (D) neitber kind, (E) resonance cannot be observed by varying w.

4. Consider a small segment of a string which is under tension T. The mass density of the string is A and the length of this segment is do. Let the vertical displacement bf the string be y(x,t) and 8y/Ox be small everywhere. The vertical force acting on this segnent is (A)(B)(C)(D)(E) none of the above.

5.Which expression cannot represent a solution of the wave equation? (A)(B)(C) (D)(E) all expressions can represent a solution of the wave equation.

8. Water (mass density ρ) fows at speed ui； through a garden hose with cross sectional area ao and emerges at pressure ps from a nozzle of cross sectional area a₀/2. The pressure at the faucet is (A)(B) (C)(D)(E) none of the above.

9. Consider N gas molecules in a cubic box of lateral size L at temperature T. Neglect the interactions between the particles and let m be the mass of a molecule, the average nunber of particles hitting one of the bounding wals per unit time is (k_B is the Boltzmann constant) (A)(B) (C) (D)(E) none of the above.

13. A long, straight wire carries a constant current I. A metal rod of length I moves at constant velocity on rails of negliglble resistance that terminate in a resistor R, as shown in the figire. The induced current in the resistor is
(A)(B)(C) (D) (E) none of the above.

14. A solenoid with N turns has a length I and a redius r. For what current will the energy density within the solenoid be u? (A)(B)(C)(D) (E) nome of the above. 

17. Light strikes a plate in an evacuated chamber. The result is that electrons are etnitted from the plate P and are collected by C. In the process a single'photon gives up all its energy to a singje electron. The maximum poasible kinetic energy of the photoelectrons, , is related to the energy of a photon, hf, by (Φ is work function) (A)(B) (C) (D) hf = 함mยma로 (E) none of the above.

19. How does the intensity of radiation changes with the distance r from the source? Let d bo the spatial dimension. (A) proportional to ,(B)proportional to , (C)proportional to, (D) proportional to (E) none of the above.

20. Here is a simple way to estimate the ground-state energy for a particle in a potential k/r. Suppoee the ground state xnomentum and position satisfies Heisenberg's uncertainty principle pr ~ h, the Kinetic energy in the ground state is Minimize the total energy of the system you find that ground state energy is roughly (A)(B)(C)(D) (E) none of the above