Physics 220 Final Exam

Transcription

1 Version 12 Summer 2012 Page 1 of 12 Physics 220 Final Exam Name: (Last) (First) (Middle) 1. Please fill out your name and your Purdue student ID on the scantron from. 2. Record 12 as your two-digit exam version number on the scantron form in the field TEST/QUIZ NUMBER 3. Write your name on this page and sign your name on the scantron form. 4. There are 20 questions. Each question is worth 15 points for 300 points. 5. This gives a total of 300 possible points.

2 Version 12 Phys 220 Final Exam Summer 2012 Page 2 of 12 Constants and Equations r F sin F B L V sub g f obs f source v 1 v v 1 v obs sound source sound Intensity Power Area

3 Version 12 Phys 220 Final Exam Summer 2012 Page 3 of 12 Constants and Equations

4 Version 12 Phys 220 Final Exam Summer 2012 Page 4 of 12 Constants and Equations Q ml U Q W PV N k B T W PV k B J/K v F T M L benefit e cost e e 1 1 Q Q T T C H C H W Q H e e Q H refrig refrig Q C H TC T T H W QC Q Q C C

5 Version 12 Phys 220 Final Exam Summer 2012 Page 5 of Five moles of nitrogen gas are conatained in an enclosed cylinder with a movable piston. If the gas temperature is 25 C and the prssure is 1.2 x 10 6 N/m 2, what is the volume? A) 4.27 x 10-2 m 3 B) 1.03 x 10-2 m 3 C) 2.34 x 10-3 m 3 D) 6.58 x 10-3 m 3 E) 8.64 x 10-4 m 3 2. A ball with a mass of 2 kg is thrown up at a 20 degree angle above the horizontal. The ball initially has a velocity of 8 m/s. How long is the ball in the air before it hits the ground? A) 0.28 s B) 0.82 s C) 1.63 s D) 0.77 s E) 0.56 s 3. A large bucket is filled with water to a height of 20 cm. After filling the bucket, a person noticed that there is a hole in the side of the bucket at the very bottom. What is the speed of the water that is coming out of the hole in the bucket? A) 0.99 m/s B) 8.47 m/s C) 3.92 m/s D) m/s E) 1.98 m/s

6 Version 12 Phys 220 Final Exam Summer 2012 Page 6 of You want to use a steel cable to two your car. Your car has a mass of 2300 kg. The cable is solid steel with a diameter of 1.4 cm and a length of 15 m. If you are pulling the car such that its acceleration is 0.9 m/s 2, how much will the cable stretch? (Steel has a Young s Modulus of 2.0 x Pa, a Shear Modulus of 8.1 x Pa, a Bulk Modulus of 1.4 x Pa) A) 1.64 cm B) 0.66 cm C) 1.57 cm D) 2.71 cm E) 1.10 cm 5. A reversible heat engine has two reservoirs, one at a temperture of 250 K, and the other at 800 K. If 8,000 J of heat is extracted from the hot reservoir, how much work is done by the engine? A) 5,500 J B) 6,825 J C) 2,500 J D) 7,250 J E) 11,636 J 6. A treasure chest filled with gold has a mass of 950 kg and is sitting at the bottom of the ocean in a place that is 10 m deep. A chain is attached to the treasure chest so that the treasure chest can be pulled up to the surface. Since the treasure chest is filled with gold, assume that the chest has the density of gold, which is 19,300 kg/m 3. The ocean water has a density of 1,025 kg/m 3. What force is required to lift the treasure chest? A) 494 N B) 900 N C) 8816 N D) 2354 N E) 9310 N

7 Version 12 Phys 220 Final Exam Summer 2012 Page 7 of A person is at a carnival and decides to ride a tilt-a-whirl, which is an amusement park ride that spins. Assume that the person is sitting in a cart that is spinning around as shown below. The person is sitting at position A. The picture on the right shown the top view of the cart. The cart is spinning counter-clockwise about the vertical axis (+y) so that a person at position A goes to the back, then to B, then to the front, and back to position A. Which of the following is the correct free body diagram for the person when are spinning but at position A? +y B back front A B back A front A) B) C) D) E) 8. A 3 kg mass is attached to a spring on a table. Assume that there is no friction. The mass oscillates with a period of 8.4 s. If the maximum amplitude of the mass is 1.2 m, what is the maximum velocity of the mass on the spring? A) 1.60 m/s B) 0.89 m/s C) 5.36 m/s D) 7.96 m/s E) 1.39 m/s

8 Version 12 Phys 220 Final Exam Summer 2012 Page 8 of The following wave is traveling on a string with a velocity of 34 m/s. What is the frequency of the wave? A) 6.0 Hz B) 11.3 Hz C) 3.7 Hz D) 5.6 Hz E) 22.5 HZ 10. A non-uniform oddly shaped board has a length of 9 m and has its center of mass at a distance of 7 m from the left end. The board is held up by a support on the left end of the board and another support on the right end of the board. If the mass of the board is 30 kg, what is the normal force that the left support must provide? A) N B) N C) N D) 23.3 N E) 65.3 N 11. As a train starts from rest and then accelerates down the track, coming toward me faster and faster, the speed of the sound waves coming toward me will be A) slower than the normal speed of sound in air. B) equal to the normal speed of sound in air. C) some constant speed faster than the normal speed of sound in air. D) increasingly faster than the normal speed of sound in air. E) increasingly slower than the normal speed of sound in air.

9 Version 12 Phys 220 Final Exam Summer 2012 Page 9 of A large cylindrical disk with a mass of 6 kg and a radius of 2 m is spinning with an angular velocity of 30 rad/s. A ring with a mass of 4 kg and a radius of 1.3 m is initally at rest and then dropped on the disk carefully so that the middle of the ring is in the same place as the middle of the disk. What is the final angular velocity of the ring and disk together? A) rad/s B) rad/s C) 8.45 rad/s D) rad/s E) rad/s 13. Two metal blocks are placed in a room and have the same initial temperature. Both blocks have the same mass, but one block is made of aluminum while the other block is made of steel. The steel block is heated by transfering an amount of heat (Q) while the aluminum block is heated by twice as much (2Q). Which of the following statements is true about the change in temperatures of the blocks? A) T of the aluminum is 2 times as much as T of the steel B) T of the aluminum is 1/2 times as much as T of the steel C) T of the aluminum is 4 times as much as T of the steel D) Both blocks have the same change in temperature. E) T of the aluminum is 1/4 times as much as T of the steel

10 Version 12 Phys 220 Final Exam Summer 2012 Page 10 of A wave is traveling on a string. A person wants to quadruple the velocity of the wave on the same string. What needs to happen to the tension on the string so that the velocity of the wave quadruples? The tension must A) increase by a factor of 16 B) increase by a factor of 4 C) increase by a factor of 2 D) decrease by a factor of 2 E) decrease by a factor of A 23 kg piece of aluminum is warmed so that its temperature increases by 7.0 C. If the same amount of heat is used to melt ice, how much grams of ice would melt? A) 36.5 g B) 65.8 g C) g D) 13.2 g E) g 16. A person is driving a truck down the road at 15 m/s when the person in front of him in a car comes to an abrupt stop. The truck crashes into the back of the car in a totally inelastic collision where the car and truck stick together. The car and truck move at a final velocity of 10 m/s immediately after the collision. Assume that the truck has a mass that is twice the car s mass. Which of the following statements about is false? A) Kinetic energy is conserved. B) Gravitational potential energy is conserved. C) The magnitude of the change in momentum of the truck is equal to the magnitude of the change in momentum of the car. D) Total energy is conserved. E) Momentum is conserved.

11 Version 12 Phys 220 Final Exam Summer 2012 Page 11 of A speaker with a power of 30 W is playing music. What is the sound intensity level of the music at a distance of 15 m? Assume that the sound can only be heard in front of the speaker and not behind it. A) 98.4 db B) 72.9 db C) db D) db E) db 18. A marble is rolling without slipping with a velocity of 3 m/s. The marble then rolls up a ramp at a 30 degree angle above the horizontal. How high up the ramp will the marble roll before coming to a complete stop? A) 0.64 m B) 0.37 m C) 0.79 m D) 0.55 m E) 0.46 m

12 Version 12 Phys 220 Final Exam Summer 2012 Page 12 of 12 Refer to the P-V diagram below for Problems 19 and 20. P (kpa) 180 D 140 C B 80 E A V (m 3 ) 19. A gas undergoes a three part process from A to D as shown in the P-V diagram above. The first part is from A to B, the second from B to C, and the third from C to D. What is the work done by the gas during this process (all three parts from A to D)? A) 52.8 kj B) kj C) 46.2 kj D) 50.4 kj E) kj 20. After going through the three part process from A to D as explained in Problem 19, the gas undergoes another two part process. Part one is from D to E, and part two is from E to A. The gas has now undergone one complete cycle and is back at A (where it started). What is the work done by the gas during the entire cycle (all fives parts A-B-C-D-E-A)? A) 19.8 kj B) kj C) 24.0 kj D) 33.0 kj E) kj