4. An incompressible fluid of density ρ is in a bucket on the elevator floor accelerating upward with acceleration a. What is the pressure difference between two points in the fluid separated by a vertical distance △h? (Gravitational acceleration is g)
(A) ρa△h
(B) ρg△h
(C) ρga△h
(D) ρ(g – a)△h
(E) ρ(g + a)△h

50. The magnitude of the magnetic field at point P for a certain clectromagnetic wave is 2.12 µT. What is the magnitude of the electric field for that wave at P ? (c = 3.0 x 108 m/s)(A)636 N/C (B)745 N/C(C) 5.23 µN/C (D) 6.36 µN/C (E)7.45 µN/C

1. 1.25 × 0.25 + 1.222 = ______. (A) 1.5345 (B) 1.535 (C) 1.53 (D) 1.5 (E) 2

2. Over a short interval near time t = 0 the coordinate of a bicycle in meters is given byx(t) = 12t – 4t3 , where t is in seconds. At the end of 1 s, what is the acceleration of the bicycle? (A) 23 m/s2 (B) 15 m/s2 (C) -4 m/s2 (D) -12 m/s2 (E) -24 m/s2

3. A 8000-N trunk is pushed along a level road by two men who apply a total forward force of 1000 N. Neglecting friction, what is the acceleration of the trunk? (Gravitational acceleration g = 10 m/s2) (A) 0.0125 m/s2 (B) 0.125 m/s2 (C) 0.8 m/s2 (D) 1.25 m/s2 (E) 8 m/s2

5. The figure shows a standing wave pattern in a string. What is the wavelength of one of the component traveling waves? (A) 10 cm (B) 20 cm (C) 40 cm (D) 60 cm (E) 120 cm

6. The figure shows four situations in which a source of sound S and a detector D are either moving or stationary. The arrows indicate the directions of motion. The speeds (when not zero) are all the same. (Note that the detector in situation ③ is stationary). Rank the situations according to the apparent frequency of the source, lowest to highest. (A) ①,②,③,④ (B) ④,③,②,① (C) ①,③,②,④ (D) ②,①,④,③ (E) ②,①,③,④

7. What is the deterministic factor of a sound wave for the sound pitch? (A) amplitude (B) frequency (C) phase (D) speed (E) intensity

8. A sample of an ideal gas is taken through the cyclic process abca shown in the figure. The scale of the vertical axis is set by At point a, T = 200 K. What is the temperature of the gas at point c? (A) 400 K (B) 600 K (C) 1419 K (D) 1800 K (E) 4258 K

9. An engine does 15 kJ of work while exhausting 37 kJ to a cold reservoir. What is the efficiency of the engine? (A) 28.8 % (B) 38.8 % (C) 68.8 % (D) 88.8 % (E) 98.8 %

10. The point P lies along the perpendicular bisector of the line connecting two long straight wires S and T that are perpendicular to the page. A set of directions A through H is shown next to the figure. When the two equal currents in the wires are directed up out of the page, the direction of the magnetic field at P is closest to the direction of ______. (A) A (B) E (C) F (D) G (E) H