112年 - 112 國立中興大學_學士後醫學系招生考試_學士後醫學系甲、乙組：物理#113978

3. Two blocks are in contact on a frictionless table. A horizontal force is applied to one block as shown. If m₁ = 2.0 kg, m₂ = 1.0 kg, and F = 3.0 N, find the force of contact between the two blocks.
(A) 1 N (B) 2 N (C) 3 N (D) 6 N(E) 9 N.

4. The accelerations of the blocks A and B respectively as scen in the situation shown in the figure are (pulleys and strings are massless and pulleys are frictionless, acceleration due to gravity is g)?
(A) 2g/3 downward, g/3 upward (B) 2g/7 downward, g/7 upward (C) 2g5 downward, g/5 upward (D) 10g/13 downward, 5g/13 upward (E) A and B are at rest.

5. For the conical pendulum shown, the 0.40 kg mass has a periodic time of 1.90 s. What is the tension in the string? (Answer in N.)
(A) 3.92 (B) 4.37 (C) 5.69 (D) 6.48 (E) 7.85.

6. An astronaut, spaced out as usual, sits in her room at position "F" on the outer rim of a wheel-shaped station as shown. Gravitational forces are negligible. The station rotates about its axis 100 times each hour as shown. She weighed 900 N on earth. Her mass has not changed, but when she stands on a spring scale at "F" it correctly reads 1000 N. Calculate the radius of the station. Answers in meters.(A) 400 (B) 360 (C) 330 (D) 280 (E) 260.

8.A uniform solid sphere of mass M and radius R rotates with an angular speed ω about an axis through its center. A uniform solid cylinder of mass M, radius R, and length 2R rotates through an axis running through the central axis of the cylinder. What must be the angular speed of the cylinder so it will have the same rotational kinetic energy as the sphere? (A)2ω/5(B) (C) 4ω/5(D)(E)

10. In the figure, a mass of 31.77 kg is attached to a light string that is wrapped around a cylindrical spool of radius 10.0 cm and moment of inertia 4.00 kg ㆍ m². The spool is suspended from the ceiling, and the mass is then released from rest a distance 5.70 m above the floor. How long does it take to reach the floor?
  (A) 10.83 s (B) 3.98 s (C) 1.14 s (D) 5.59 s (E) 7.89 s.

11. A uniform sign is supported against a wall at point P as shown in the figure. If the sign is a square 0.4 m on a side and its mass is 4.0 kg, what is the magnitude of the horizontal force that the wall at P experiences?
(A) 5.8 N (B) 10.0 N (C) 20 N (D) 98 N (E) 75 N.

12. A 2.0 kg block on a frictionless table is connected to two ideal massless springs with spring constants k₁ and k₂ whose opposite ends are fixed to walls, as shown in the figure. What is the angular frequency of the oscillation if k₁=7.6 Nm and k₂=5.0 N/m?
(A) 2.5 rad/s (B) 3.5 rad/s (C) 0.40 rad/s (D) 0.56 rad/s(E) 5.5 rad/s.

13. In the figure, two masses, M = 16 kg and m = 12.8 kg, are connected to a very light rigid bar and are attached to an ideal massless spring of spring constant 100 N/m. The system is set into oscillation with an amplitude of 78 cm. At the instant when the acceleration is at its maximum, the 16-kg mass separates from the 12.8-kg mass, which then remains attached to the spring and continues to oscillate. What will be the amplitude of oscillation of the 12.8-kg mass?
(A) 35 cm (B) 62 cm (C) 78 cm (D) 98 cm (E) 110 cm.

14. A standing wave is oscillating at 690 Hz on a string, as shown in the figure. What is the speed of traveling waves on this string?
(A) 140 m/s (B) 210 m/s (C) 280 m/s (D) 340 m/'s (E) 410 m/s. 60cm

18. A heat conducting rod, 0.90m long, is made of an aluminum section that is 0.10 m long, and a copper section that is 0.8 m long. Both sections have cross-sectional areas of 0.0004 m². The aluminum end is maintained at a temperature of 40℃ and the copper end is at 150 ℃ . The thermal conductivity of aluminum is 205 W/m•K and of copper is 385 W/m•K. Steady state has been reached, and no heat is lost through the well-insulated sides of the rod. The temperature of the aluminum-copper junction in the rod is closest to (A) 61℃ .(B) 48℃ .(C) 56℃ .(D) 34℃ .(E) 70℃ .

20. If we double the root-mean-square speed (thermal speed) of the molecules of a gas, then (A) its temperature must increase by a factor of 4. (B) its temperature must increase by a factor of 2. (C) its temperature must incrcase by a factor of(D) its pressure must increase by a factor of 2. (E) its pressure must increase by a factor of 4.

22. The graph in the figure shows a cycle for a heat engine for which Q_H= 35 J.
What is the thermal efficiency of this engine?
(A) 14% (B) 21 % (C) 29%(D) 35%(E) 49 %.

25. A certain spherical asteroid has a mass of 3.5 x 10¹⁶ kg and a radius of 8.8 km. What is the minimum speed needed to escape from the surface of this asteroid? (G = 6.67 x 10^-11N● m²/kg²) (A) 223 m/s (B) 126 m/s (C) 52 m/s (D) 34 m/s (E) 23 m/s.

26. A loop of wire (resistance = 2.0 mΩ) is positioned as shown with respect to a long wire that carries a current. If d = 1.0 cm , D =6.0 cm, and L= 1.5 m, what current in mA is induced in the loop at an instant when the current in the wire is increasing at a rate of 100 A/s?
(A) 34 (B) 30 (C) 27 (D) 38 (E) 0.50.

27. Current enters a circular loop as shown below. At point P, where x = a, the magnetic field has the value . The value of the magnetic field at x = -a is:
(A)0(B)(C)(D) (E)i.

28. Determine the equivalent capacitance in pF for the network shown when C = 12 pF.
(A) 34 (B) 17 (C) 51 (D) 68 (E) 21.

30. The distance from an antinode to a node nearest to that antinode is (A) (B)(C)λ(D)2λ(E)3λ.

32. The xy plane is "painted" with a uniform surface charge density equal to 40 nC/m² . Consider a spherical surface with a 4.0 cm radius that has a point in the xy plane as its center. What is the electric flux in Nm²/C for that part of the spherical surface for which z ＞ 0? (ε_o=8.85x10^-12 C²/Nm²) (A) 14 (B) 11 (C) 17 (D) 20 (E) 23.

33. A charged conductor has the oval shape shown below. When we compare the potential at points A and B, we find that:
  (A) V_A＞V_B (B) V_A=V_B (C) V_A＜V_B(D) V_A≤V_B(E) we must first determine the charge distribution on the surface before we can calculate the potential difference between two points on the surface.

34. Three charges, the outer two +q, and the inner one -9, are placed in a line, as shown below. The potential energy of these charges is
(A)(B)(C)(D)(E)

36. A 30 turn square coil (length of side = 12 cm ) with a total resistance of 2.5 Ω is placed in a uniform magnetic field directed perpendicularly to the plane of the coil. The magnitude of the field varies with time according to B= Ae^8t, where A = 50 mT and t is measured in seconds. What is the magnitude in V of the induced emfin the coil at t = 0? (A) 0.31 (B) 0.27 (C) 0.17 (D) 0.20 (E) 22 x 10^-3.

37. Charge Q is spread uniformly along the circumference of a circle of radius R. A point particle with charge q is placed at the center of this circle. The total force exerted on the particle can be calculated by Coulomb's law: (A) just use R for the distance (B) just use 2R for the distance (C) just use 2πR for the distance (D) the result of the calculation is zero (E) none of the above.

38. A solid insulating sphere of radius R contains positive charge that is distributed with a volume charge density that does not depend on angle but does increase with distance from the sphere center. Which of the graphs below might give the magnitude E of the electric field as a function of the distance r from the center of the sphere? (A)(B)(C)(D)(E)

40. Points R and T are each a distance d from each of two particles with equal positive charges as shown. If k_e =, the work required to move a particle with charge q from R to T is:
  (A)0(B) k_eQq/d²(C)keQq/d(D)(E) k_eQq/(2d).

41. A metal bar sliding on parallel rails a length apart from one another is given initial velocity v_o to the right. The rails are connected by a resistor of resistance R at their left. If a constant magnetic field B is directed into the page, what is the magnitude of the force on the rod? (A) (B) (C)(D) (E)

42. An alpha particle is a nucleus of helium. It has twice the charge and four times the mass of the proton. When they were very far away from each other, but headed toward directly each other, a proton and an alpha particle each had an initial speed of 0.0030c, where c is the speed of light. What is their distance of closest approach? (c = 3.00 x 10⁸ m/s, k_e = 1/4πε₀ = 8.99 x 10⁹ N ●m²/C², e = 1.60 x 10^-19 C, ^mproton = 1.67 x 10^-27kg) (A) 2.1 x 10^-13 m (B) 3.3 x 10^-13 m (C) 2.6 x 10^-13 m (D) 2.9 x 10^-13 m (E) 4.2x 10^-13 m.

43. The figure shows a 2.0-cm diameter roller that turns at 90 rpm. A 4.0-cm wide plastic film is being wrapped onto the roller, and this plastic carries an excess electric charge having a uniform surface charge density of 5.0 nC/cm². What is the current of the moving film?
(A) 190 nA (B) 23 μA (C) 30 nA (D) 11  μA (E) 16 nA.

44. The heater element of a particular 120-V toaster is a 8.9-m length of nichrome wire, whose diameter is 0.86 mm. The resistivity of nichrome at the operating temperature of the toaster is 1.3 x 10-6 Ω. If the toaster is operated at a voltage of 120 V, how much power does it draw? (A) 720 W (B) 700 W (C) 750 W (D) 770 W (E) 800 W.

45. The figure shows a velocity selector that can be used to measure the speed of a charged particle. A beam of particles is directed along the axis of the instrument. A parallel plate capacitor sets up an electric feld E, which is oriented perpendicular to a uniform magnetic field B. If the plates are separated by 2.0 mm and the value of the magnetic field is 0.60 T, what voltage between the plates will allow particles of speed 5.0 x 10⁵ m/s to pass straight through without deflection?(A) 94 V (B) 1900 V (C) 3800 V (D) 190 V (E) 600 V.

46. As shown in the figure, a wire and a 10-Ω resistor are used to form a circuit in the shape of a square, 20 cm by 20 cm. A uniform but nonsteady magnetic field is directed into the plane of the circuit. The magnitude of the magnetic field is decreased from 1.50 T to 0.50 T in a time interval of 63 ms. The average induced current and its direction through the resistor, in this time interval, are closest to
(A) 63 mA, from b to a (B) 38 mA, from b to a (C) 63 mA, from a to b (D) 38 mA, from a to b (E) 95 mA, from a to b.

48. Light of wavelength 500 nm illuminates a round 0.50-mm diameter hole. A screen is placed 6.3 m behind the slit. What is the diameter of the central bright area on the screen? (A) 15 mm (B) 270 μm (C) 7.7 mm (D) 3800 μm (E) 5 mm.

50. What resistance should be added in series with a 3.0-H inductor to complete an LR circuit with a time constant of 4.0 ms? (A) 20 Ω (B) 0.75 kΩ  (C) 12 Ω  (D) 0.75Ω (E) 2.5Ω