2. The mass in the figure slides on a frictionless surface. If m = 2 kg, k1 = 800 N/m, and k2 = 450 N/m, what is approximate the frequency of oscillation (in Hz)?
(A) 2
(B) 4
(C) 6
(D) 8
(E) 10

298 氧氣濃度低於18%之缺氧環境，應使用那一類呼吸防護具？ (A)供氣式 (B)過濾式 (C)供 氣式與過濾式皆可 。

299 液化石油氣為易燃氣體，閃火點-104.47度，屬於第幾類危險物品？(A)第1類 (B)第2類 (C)第3類 。

300 禁水性物質標誌的背景顏色為 (A)黃色 (B)藍色 (C)白色 。

1. The horizontal surface on which the objects slide is frictionless. If M = 5.0 kg, the tension in string 1 is 60 N. Determine F. (A) 20 N (B) 24 N (C) 30 N (D) 34 N (E) 48 N

3. A pivoted bar has a weight of 10 kg and a length of 1 meter, and is supported by a cable, as shown below. What is the tension force of the cable when a 50 N box is hung at the end of the bar? (A) 150 N (B) 295 N (C) 410 N (D) 570 N (E) 775 N

4. A circular track of radius 1000 meters is banked at 30 degrees without any friction. What is required speed for a car to keep running on the circular track? (A) about 30 m/s (B) about 45 m/s (C) about 55 m/s (D) about 65 m/s (E) about 75 m/s

5. Two point masses 1 kg and 2 kg are on a massless bar with axis of rotation through the center of length 2 meters, and a sphere of radius 10 cm and of mass 100 kg is on the center of the bar, as shown below. What is the moment of inertia (kg∙m2 )? (A) 3.33 (B) 3.4 (C) 3.5 (D) 3.67 (E) 4

6. The disk A with moment of inertia I1 rotates with angular speed ω1 about a vertical frictionless axle. A second disk B with moment of inertia I2 rotates with angular speed ω2 drops on the disk A. Since two disks are rough and two disks eventually reach the same angler speed ω, what is the final angular speed ω? (A) (I1ω1+ I2ω2)/I1 (B) (I1ω1)/(I1+ I2) (C) (I1ω1+ I2ω2)/( I1+ I2) (D) (I2ω2)/( I1+ I2) (E) (I1ω1− I2ω2)/( I1+ I2)

7. The same force F is applied horizontally to bodies 1, 2, 3, and 4, of masses m, 2m, 3m, and 4m, initially at rest and on a frictionless surface, until each body has traveled distance d. The correct listing of the magnitudes of the velocities of the bodies, are . (A) (B) (C) (D) (E)

8. What is the entropy change for one mole ideal gas that expands from volume V to 4V in a free expansion process? (A) 4 R (B) 2 R (C) (ln4) R (D) (ln2) R (E) R