Physics 101 Final Exam Answer Key 2004

Physics 101 Final Exam Answer Key 2004 - Dr. Huerta Phy 101...

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Unformatted text preview: Dr. Huerta Phy 101 ANSWER KEY Final Exam Form 1 8 December 2004 CORRECT CHOICES ARE MARKED BY [X] Fall Semester 2004, Sections S and T THIS IS FORM ONE (1) IN THE COMPUTER GRADING SHEET MARK YOUR LAST NAME, I.D. NUMBER, AND FORM NUMBER (FM). USE A #2 PENCIL. BUBBLE IN YOUR BEST ANSWER FOR All 30 QUESTIONS. EACH QUESTION IS WORTH 5 POINTS. TURNING IN THE ANSWER SHEET WILL CONSTITUTE YOUR HONOR PLEDGE THAT YOU HAVE NEITHER GIVEN NOR RECEIVED ANY AID ON THIS TEST. YOU MAY ONLY USE A SIMPLE CALCULATOR, NOT CAPABLE OF STORING TEXT. YOU MAY BE ASKED TO SHOW YOUR PHOTO ID DURING THE EXAM. ALWAYS USE g = 10 m/s2 . [1] A floating ship has a mass of 107 kg. When the ship is loaded with 3 × 106 kg of cargo, how much more of the ship’s volume will become submerged? [X] 3 × 103 m3 . [B] 3 × 102 m3 . [C] 10.3 × 104 m3 . [D] 3 × 103 kg. [E] 3 × 102 kg. [2] A pipe carries water in steady flow. The speed of the water is 0.5 m/s at a place where the diameter is 2 inches. The pipe then splits into two thinner pipes of diameter 1 inch each. The speed of the water in one of the thin pipes is [A] 0.13 m/s [B] 0.25 m/s [C] 0.5 m/s [X] 1 m/s [E] 2 m/s [3] A manometer consists of a U-shaped tube with water in it. One end of the U-tube is connected to a container filled with a gas at a pressure Pgas . The other end is open to the atmosphere. The water is 50 cm higher in the part open to the atmosphere than in the part connected to the gas. Find the gauge pressure of the gas Pgauge ≡ Pgas − Patm . [A] 105,000 Pa [B] -105,000 Pa [C] 95,000 Pa [X] 5 × 103 Pa [E] −5 × 103 Pa [4] A jogger did 400,000 J of work and gave off 360,000 J of heat to the environment. The change ∆U in the internal energy of the jogger was [A] -40,000 J [B] 40,000 J [X] -760,000 J [D] 760,000 J [E] zero [5] A steel tank with a volume of 50.0 gallons is filled with gasoline when the temperature is 5.00◦ C. It is flown the next day to a place where the temperature is 30.0◦ C. How much gasoline will spill from the tank if it has an escape valve? The volume expansion coefficient for gasoline is β = 950 × 10−6 ◦ C−1 ; for steel it is β = 36.0 × 10−6 ◦ C−1 . [X] 1.14 gallons [B] 1.19 gallons [C] 1.23 gallons [D] 1.37 gallons [E] none of the above [6] The Celsius and Fahrenheit temperatures will have the same numerical value when [A] TC = −5◦ C [B] TC = 5◦ C [X] TC = −40◦ C [D] TC = 40◦ C [E] no such temperature. Physics 101 Final Exam Form 1 8 December 2004 Dr. Huerta Phy 101 ANSWER KEY Final Exam Form 1 8 December 2004 [7] The spring in a pop gun with a spring constant of k = 100 N/m is compressed 0.1 m and suddenly released as it pushes a 0.25 kg ball. With what speed will the ball leave the gun? [X] 2 m/s [B] 1.4 m/s [C] 4 m/s [D] 20 m/s [E] 40 m/s [8] How much sweat would have to evaporate from the body of the above jogger in problem [4] to get rid of all the heat by evaporation? [A] 0.34 kg [X] 0.16 kg [C] 0.18 kg [D] 0.018 kg [E] 0.016 kg [9] A 350-gm piece of metal at 100◦ C is dropped into a 100-gm aluminum cup containing 500 gm of water at 15◦ C. the final temperature of the system is 40◦ C. What is the specific heat of the metal, assuming no heat is exchanged with the surroundings. The specific heat of water is 4186 J/(kg·K) and of aluminum it is 900 J/(kg·K). [A] 4636 J/(kg·K) [B] 3600 J/(kg·K) [C] 3300 J/(kg·K) [X] 2600 J/(kg·K) [E] 1900 J/(kg·K) [10] What volume is occupied by 2 moles of gas at 546 K and twice atmospheric pressure? [A] 89.6 × 10−3 m3 [B] 179.2 × 10−3 m3 [C] 11.2 × 10−3 m3 [D] 22.4 × 10−3 m3 [X] 44.8 × 10−3 m3 [11] If you double the absolute temperature of an ideal gas, the average kinetic of the molecules [A] is multiplied by 4 [X] is multiplied by 2 [C] is multiplied by 1 2 √ 1 [D] is multiplied by √2 [E] is multiplied by 2 [12] An empty box in the shape of a cube of side L stands on the floor. The top of the box is missing. Neglecting the thickness of the material, find how far from the floor is the center of mass of the box. [A] 0.1L [B] 0.2L [C] 0.3L [X] 0.4L [E] 0.5L [13] A system consisting of an ideal gas at the constant pressure of 2 × 105 Pa gains 5000 J of heat while in the process the internal energy increases by 3000 J. Find the change ∆V in the volume of the system. [A] −40−2 m3 . [B] 40−2 m3 . [C] 25−2 m3 . [X] 10−2 m3 . [E] −10−2 m3 . [14] A molecule of mass m collides with a wall that is normal to the x axis as shown in the figure below. Initially the molecule has a positive x component of velocity, vx > 0. The molecule bounces from the wall with the same vy and vz as initially, but the x component is reversed. The molecule receives an impulse Imol , and the wall receives an impulse Iwall due to the collision. The impulse to the wall, Iwall , is given by m ˆ ˆ [A] − 2m|vx |x [X] 2m|vx |x ˆ [D] m|vx |x [E] zero Physics 101 Final Exam Form 1 wall ˆ [C] − m|vx |x x 8 December 2004 Dr. Huerta Phy 101 ANSWER KEY Final Exam Form 1 8 December 2004 [15] Circle the answer that best represents the vector Q − P in the figure below. P [X] [B] [C] [D] Q [E] [A] [B] [C] [D] [E] [16] Two cars, A and B, traveling in the opposite directions are 500 m apart. The speed of B is 20 m/s, and the speed of A is 30 m/s. In how much time will they meet? [A] 4 s [B] 5 s [X] 10 s [D] 20 s [E] 50 s [17] The three men called A, B and C are at rest. Each man weighs 1000 N. Each man exerts a force of 100 N toward the left against the floor. The horizontal force that C exerts on the wall is A [A]100N [B]200N [X]300N [D]400N C B [E]600N [18] A 100 kg man pulls his 50 kg dancing partner toward himself with a force of 100 N. While she is being pulled, the force that the 50 kg woman exerts on the man is [A] 150 N [X] 100 N [C] 50 N [D] 0 N [E] not enough information to answer. [19] Three blocks of equal mass m are sliding with acceleration a on a frictionless surface. The tension in ropes A, B, and F are m A m B m F [A] TA = ma, TB = ma, F = ma [B] TA = ma, TB = ma, F = 2ma [C] TA = ma, TB = ma, F = 3ma [D] TA = ma, TB = 2ma, F = 2ma [X] TA = ma, TB = 2ma, F = 3ma [20] A 100 kg man pushes a 50 kg box with an acceleration of 0.2 m/s2 along a horizontal surface while exerting a horizontal force of 200 N. The force of friction on the box is [A] 10 N [X] 190 N [C] 200 N [D] 210 N [E] insufficient information. [21] A rifle of mass M fires a bullet of mass m and recoils. Let the kinetic energy of the bullet in flight be Kb and the kinetic energy of the recoiling rifle be Kr . The kinetic energies are related as m m3 [A] Kr = 1 [B] Kr = −1 [C] Kr = M [X] Kr = M [E] Kr = M 2 Kb Kb Kb m Kb Kb [22] Fluid is flowing steadily along a wide pipe that becomes narrower. As the fluid passes from the wide part to the narrow part [A] the speed decreases and the pressure decreases. [B] the speed decreases and the pressure increases. [C] the speed increases and the pressure remains the same. [D] the speed increases and the pressure increases. [X] the speed increases and the pressure decreases. Physics 101 Final Exam Form 1 8 December 2004 Dr. Huerta Phy 101 ANSWER KEY Final Exam Form 1 8 December 2004 [23] A particle undergoes a displacement ∆r = −2x + 5y meters while it is being acted upon ˆ ˆ by a total force F = 7x + 4y Newtons. The initial kinetic energy of the particle was 8 J. ˆ ˆ The kinetic energy after the displacement is [A] 6 J [X] 14 J [C] 28 J [D] 20 J [E] insufficient information. [24] A rifle is aimed horizontally at the center of a target located 100 meters away. The bullet leaves the rifle with a speed of 1000 m/s. How far below below the center of the target does the bullet hit? [X] 5 cm [B] 10 cm [C] 50 cm [D] 1 cm [E] 0 cm [25] A particle with a mass of 0.5 kg is oscillating attached to a spring. Its position is given by x(t) = (0.05 m) cos[(10 rad/s)t]. Find the maximum speed, vmax , of the particle in its motion and the k constant of the spring. Note that x is in meters, and t is in seconds. [A] vmax = 0.05 m/s, and k = 5 N/m [B] vmax = 0.05 m/s, and k = 100 N/m [X] vmax = 0.5 m/s, and k = 50 N/m [D] vmax = 5 m/s, and k = 50 N/m [E] vmax = 0.5 m/s, and k = 5 N/m [26] A wheel of a car has a diameter of 2 ft. The car is moving with a speed of 60 miles/hour. If the wheel is rolling without slipping, the angular velocity of the wheel is approximately (1 mile = 5280 ft) [A] 176 rad/sec [X] 840 rpm [C] 14 rad/sec [D] 44 rad/sec [E] 14 rpm [27] The rigid L-shaped object in the figure below consists of three small (point) masses connected by light (massless) rods of lengths a and b. What torque τy must be applied to make this object rotate about the y axis with an angular acceleration αy ? y m3 z axis out of the paper a m b 1 m x 2 [A] τy = (m1 + m2 + m3 )a2 αy [B] τy = (m2 b2 + m3 a2 )αy [D] τy = (m1 + m3 )a2 αy [X] τy = m2 b2 αy [C] τy = m3 a2 αy [28] A space traveler weighs 1000 N on Earth. What will the traveler weigh on another planet with the same mass density as the earth, but whose radius is twice that of the Earth? [A] 1000 N [B] 500 N [C] 4000 N [X] 2000 N [E] 250 N Physics 101 Final Exam Form 1 8 December 2004 Dr. Huerta Phy 101 ANSWER KEY Final Exam Form 1 8 December 2004 [29] A mass m hangs from a massless rope wound around a cylindrical shaft of mass M , radius R and moment of inertia I = M R2 /2, as shown in the figure below. The mass is released from rest and falls as the rope unwinds without slipping and the shaft rotates without friction around its axis. Use energy considerations to find that after the mass has fallen a height h, the speed v is given by M R [A] v = 2gh [B] v = D] v = 2mgh m+M 2mgh M [X] v = [C] v = 4mgh M m 4mgh 2m + M h [30] An amusement park ride swings a rider of mass m on a horizontal circle of radius R with a constant speed v as shown in the figure below. Given θ, g, R, and m, the speed v is given by θ T R m √ [A] v = rg sin θ √ [E] v = rg [B] v = √ rg cos θ Physics 101 Final Exam Form 1 [X] v = √ v rg tan θ [D] v = rg tan θ 8 December 2004 ...
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This note was uploaded on 10/11/2011 for the course PHY 101 taught by Professor Ashkenkai during the Fall '08 term at FIU.

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