Phys102 First Major-112 Zero Version Coordinator: Wednesday, March 07, 2012 Page: 1

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1 Coordinator: Wednesday, March 07, 01 Page: 1 Q1. A transverse sinusoidal wave, travelling in the positive x direction along a string, has an aplitude of 0 c. The transverse position of an eleent of the string at t = 0, x = 0 is y = c, and the eleent has negative velocity. What is the phase constant of this wave? A) 0.15 rad B) 6.1 rad C) 1.4 rad D) 0.9 rad E) 0.14 rad Q. A transverse sinusoidal wave on a string is described by the wave function y (x,t) = 0.15 sin (0.80x 50t), where x and y are in eters and t is in seconds. The ass per unit length of the string is 1 g/. What is the average power transitted by the wave? A) 1 W B) 4 W C) 10 W D) 14 W E) 3 W Q3. Two identical sinusoidal transverse waves travel along a stretched string. Each wave has an aplitude y and wavelength λ. If the phase difference between the two waves is 0.0 λ, what is the aplitude of the resultant? A) 1.6 y B) 0.80 y C) 0.45 y D) 3.5 y E) 4.8 y Q4. A standing wave, having three nodes, is set up on a string fixed at both ends. If the frequency of the wave is doubled, how any antinodes will there be? A) 4 B) 3 C) 5 D) 6 E) 7 Q5. A sound wave enters a tube at the source end, as shown in figure 1. At point P, the sound wave splits into two waves that recobine at point Q. The radius of the seicircle is varied until the first iniu is observed at the detector when r = 50.0 c. What is the wavelength of sound?

2 Coordinator: Wednesday, March 07, 01 Page: P Q A) 114 c B) 8 c C) 456 c D) 15 c E) 304 c Q6. A source eits sound with equal intensity in all directions. If the displaceent aplitude is doubled, the sound level increases by A) 6 db B) 3 db C) db D) 4 db E) 5 db Q7. A tuning fork with a frequency of 51 z is placed near the top of the tube shown in figure. The water level is lowered, by opening the valve, so that the length L slowly increases fro an initial value of 0.0 c. Deterine the next value of L that corresponds to a resonance. Take the speed of sound in air to be 343 /s. A) 50. c B) 16.7 c C) 83.7 c D) 117 c E) 33.5 c Q8. A block, with a speaker attached to it, is connected to a spring and oscillates on a frictionless table between points A and B, as shown in figure 3. The speaker eits sound that is received by a person. The closest point of the block to the person is A, the farthest point is B, and O is

3 Coordinator: Wednesday, March 07, 01 Page: 3 the equilibriu point of the spring (neither stretched nor copressed). What position of the speaker corresponds to the highest frequency observed by the person? A) Point O travelling to the right. B) Point O travelling to the left. C) Point A. D) Point B. E) The frequency is the sae everywhere. Q9. A block of ice, with a ass of 6.30 kg at 0.00 o C, is added to a certain aount of water. The water is cooled fro 100 to 0.00 o C. What is the ass of water used? Assue that all the ice elted. A) 5.01 kg B).04 kg C) 3.4 kg D) 1.50 kg E) 6.05 kg Q10. Consider a copper slab of thickness 19 c and cross sectional area 5.0. eat is conducted fro the left to the right of the slab at a rate of 1. MW. If the teperature on the left of the slab is 10 o C, what is the teperature on the right of the slab? (The theral conductivity of copper is 400 W/ K) A) 1 o C B) +1 o C C) 0 o C D) +0 o C E) +4 o C Q11. Consider benzene liquid filling copletely a steel container of volue 100 c 3 at 0.0 o C. Calculate the coefficient of volue expansion of benzene when 0.37 c 3 of benzene spills over fro the tank as its teperature is raised to 50.0 o C. (Neglect the theral expansion of the container) A) /C o B) 3.68 x 10-4 /C o C) 5.3 x 10-4 /C o

4 Coordinator: Wednesday, March 07, 01 Page: 4 D).34 x 10-5 /C o E) 4.33 x 10-4 /C o Q1. Which of the following stateents are WRONG? 1. Two objects are in theral equilibriu if they have the sae teperature.. In an isotheral expansion, the work done by the gas is equal to the change in its internal energy. 3. In an adiabatic process, heat lost by the gas is equal to the work done on the gas. 4. In an isochoric process, heat exchanged is equal to the change in internal energy of the gas. A) and 3 B) 1 and C) 1 and 3 D) 1 and 4 E) and 4 Q13. Consider an isotheral copression of an ideal gas at a teperature of 0.00 o C. The initial pressure of the gas is 1.0 at and the final volue is 1/5 the initial volue. Find the nuber of oles of the gas if it loses 365 J of heat during the process. A) 0.10 oles B) 0.63 oles C).0 oles D) 3.4 oles E) 1.5 oles Q14. For a teperature increase of ΔT, a certain aount of a onatoic ideal gas requires 50 J of heat when heated at constant volue, and 83 J of heat when heated at constant pressure. ow uch work is done by the gas in the second situation? A) 33 J B) 130 J C) 67 J D) 90 J E) 50 J Q15. Figure 4 shows a cycle undergone by 1.0 ole of an ideal diatoic gas. The teperatures are T 1 = 400 K, T = 700 K, and T 3 = 555 K. Calculate the net work done in one cycle.

5 Coordinator: Wednesday, March 07, 01 Page: 5 A) 1.7 kj by the gas B) 1.7 kj on the gas C) 3.8 kj on the gas D) 3.8 kj by the gas E) 0.5 kj by the gas Q16. The teperature of an ideal gas is reduced fro 100 o C to 0 o C. The rs speed of its olecules decreases by: A) 11% B) % C) 47% D) 55% E) 71% Q17. Two oles of a onatoic ideal gas are taken through the cycle shown in figure 5. The change in entropy in going fro b to c is: A) J/K B) 17.3 J/K C).17 J/K D) 34.6 J/K E) J/K Q18. In four experients, 3 oles of an ideal gas undergo reversible isotheral expansions, starting fro the sae volue but at different teperatures. The corresponding p-v plots are shown in figure 6. Rank the four situations a, b, c, and d according to the change in the entropy of the gas, greatest first.

6 Coordinator: Wednesday, March 07, 01 Page: 6 A) (a and c) tie, then (b and d) tie. B) a, then b, then c, then d. C) d, then c, then b, then a. D) (b and d) tie, then (a and c) tie. E) (a and d) tie, then (b and c) tie Q19. A Carnot engine whose cold reservoir is at 15 o C has an efficiency of 34%. Then, the teperature of the hot reservoir is fixed while that of the cold reservoir is decreased. What should the teperature of the cold reservoir be in order to ake the efficiency of this engine equal to 36%? A) 6.3 o C B) 80 o C C) 160 o C D) 7. o C E) 1 o C Q0. A Carnot air conditioner takes heat fro a roo at 1 C and transfers it to the outdoors, which is at 35 C. For each two joules of electric energy required to operate the air conditioner, how any joules are reoved fro the roo in the for of heat? A) 4 J B) 1 J C) 1.7 J D) 3.3 J E).0 J

7 Physics 10 Major1 Forula sheet v v ω = λf = k τ = µ y = y sin(kx ωt ± φ) + v = B ρ 1 P = µω y v S = S cos( kx ωt) P = P sin( kx ωt ); where P = ρ vωs 1 I = ρ ( ωs ) v I β = 10 log, I o = 10-1 W/ I o Power I = Area f v vd = f ± v± vs φ φ y = y cos sin kx ωt + y = (y sinkx) ωt cos nv f n =, L n = 1,,3,... nv f n =, 4L n = 1,3,5... ΔL = αlδt ΔV = β VΔT PV = nrt = NkT λ ΔL = φ π ΔL = λ = 0,1,,. 1 ΔL = + λ, = 0,1,,.. γ γ 1 PV = constant; TV = constant 3 C = R for onatoic gases, v 5 = R for diatoic gases. 9 T = T + 3 F 5 C Q = L Q = c T Q = nc T = Q W ΔE int ΔE int = nc VΔT C p - C v = R W = PdV Q T Pcond = = ka t v ( 3/)kT =, W = Q Q L W Q L ε = = 1- Q Q -T L QL K = W Q L T = L, = Q T dq S T Constants: C v rs = 3RT M 1 Liter = R = 8.31 J/ol K N A = 6.0 x 10 3 olecules/ole 1 at = 1.01 x 10 5 N/ k = 1.38 x 10-3 J/K 1 calorie = Joule g = 9.8 /s for water: J J cw = 4190 ; cice = 0 kg.k kg. K 5 J 6 J LF = , LV = kg kg