55. The gravitational acceleration at the surface of Earth is g. Another planet has the density of Earth but twice the radius. What is the gravitational acceleration at the surface of the planet?
(A)8g
(B) 4g
(C) 2g
(D)g
(E) g/4

51. The intensity of electromagnetic energy 3 m from the point source is 100 W/m2. What is the intensity 30 m away? (A) 1000 W/m2 (B) 100 W/m2 (C) 10 W/m2 (D) 1 W/m2 (E) 0.1 W/m2

52. If the distance between the first and the tenth minima of the double-slit pattern is 18.0 mm and the slits are separated by 0.150 mm with the screen 50.0 cm from the slits, what is the wavelength of the light used? (A) 400 nm (B) 500 nm (C) 600 nm (D) 700 nm (E) 800 nm

53. A 29.5-kg boy standing still on a frictionless surface catches a 500-g dodgeball with velocity = (20.0 m/s). What is the total energy loss of the system(the boy and the dodgeball)? (A) 16.7 J (B) 48.0 J (C) 98.3 J (D) 67.6 J (E) Not enough information

54. A block with mass 0.5 kg is forced against a horizontal spring of negligible mass, compressing the spring with a distance of 0.2 m. When the block is released, the block moves on a horizontal tabletop for 1.0 m before coming to rest. The force constant of the spring is 100 N/m. What is the coefficient of kinetic friction between the block and the tabletop? (A)0.16(B) 0.25 (C)0.32(D) 0.41 (E) 0.53

56. The left column of a U-tube is filled with liquid A of density ρA, and the right column is filled with another liquid B of density ρB = ρA/3. How much higher is the liquid in the right column than in the left one (see figure right)?(A)h=6cm (B)h=4cm (C)h=3cm (D)h=2 cm (E)h=1 cm

57. An ideal gas undergoes a reversible isothermal expansion. The change in entropy △S of the gas versus the volume of the gas is shown on the right. When Y'is expanded from 0.5m3 to 2 m3. △S =3 J/K. How many moles are in the sample? (The gas constant is R-8.3 J.K-1·mol-1)(A) 10 mol (B) 49.8 mol (C) 0.26 mol (D) 3.74 mol (E) 104.3 mol

58. An ideal monatomic gas undergoes the following reversible process (a→b). How much energy of heat is absorbed by the gas?(A)T0S0 (B)T0S0/2 (C)4T0S0 (D)3T0S0/2 (E)0

59. Two conducting spheres with radius r and 3r are separated far-apart. The larger sphere carries charge Q, while the smaller one is neutral. After the two spheres are connected by a conducting wire, what are the charges QS and QL carried by the smaller sphere and larger sphere, respectively? (A) QS = 15Q/16 andQL = Q/16 (B) QS = 9Q/10 and QL = Q/10 (C) QS = Q/10 and QL= 9Q/10 (D) QS = Q/16 andQL= 150/16 (E) QS = Q/4 and QL= 3Q/4

60. What is the electrical oscillations angular frequency in an inductance-capacitor circuit? Assume L is the inductance and C is capacitance.(A)(B)(C)(D)(E)

61. Which symbol is used to denote the coupling between non-equivalent hydrogen atoms on adjacent carbon atoms in NMR spectroscopy? (A)J (B)Hz (C)δ (D)eV (E) ppm