Physics I Exam with Problems on Mechanics and Formula Sheet, Exams of Physics

Download Physics I Exam with Problems on Mechanics and Formula Sheet and more Exams Physics in PDF only on Docsity! Name ________________________________________________________________________ 1 Exam #2 Physics I Spring 2006 If you would like to get credit for having taken this exam, we need your name (printed clearly) at the top and section number below. Your name should be at the top of every page. Section # _____ 1 M/R 8-10 (Bedrosian) _____ 2 M/R 10-12 (Hayes) _____ 3 M/R 10-12 (Eah) _____ 4 M/R 12-2 (Bedrosian) _____ 5 M/R 2-4 (Hayes) _____ 7 M/R 4-6 (Hayes) _____ 9 T/F 10-12 (Wilke) _____ 10 T/F 10-12 (Washington) _____ 11 T/F 12-2 (Yamaguchi) _____ 12 T/F 2-4 (Wetzel) _____ 14 M/R 12-2 (Eah) _____ 15 T/F 12-2 (Wilke) You may not unstaple this exam. Only work written on the same page as the question will be graded. Cheating on this exam will result in an F in the course. Questions Value Score Part A 32 B-1 20 B-2 24 C-1 24 Total 100 Name ________________________________________________________________________ 2 On this exam, please neglect any relativistic and/or quantum mechanical effects. If you don’t know what those are, don’t worry, we are neglecting them! On all multiple-choice questions, choose the best answer in the context of what we have learned in Physics I. On graphing and numerical questions, show all work to receive credit. For each question, please assume we have given you enough information to answer it. Part A – Multiple Choice – 32 Points Total (8 at 4 Points Each) Write your choice on the line to the left of the question number. Questions 1-4 below refer to the following situation: Professor Bedrosian is standing on a turntable holding a dumbbell at arm’s length in each hand and rotating as shown in Figure A. He then pulls the dumbbells closer to his body while continuing to rotate as shown in Figure B. The system consists of Professor Bedrosian, the turntable, and the dumbbells. The turntable is free to rotate and friction in its bearings can be neglected. All quantities are to be taken with respect to the axis of rotation. For each of the quantities listed in questions 1-4, put A if the quantity is greater in configuration A, B if the quantity is greater in configuration B, or C if they are equal. For vector quantities, we are interested in the magnitude. ______ 1. Angular Velocity. ______ 2. Angular Momentum. ______ 3. Rotational Inertia. ______ 4. Rotational Kinetic Energy. BA Name ________________________________________________________________________ 5 B-2 – Graphing – 24 Points An object of mass m = 0.5 kg begins at time t = 0 s moving at 3.0 m/s in the +X direction at location (0.0, 4.9, 0.0) m. The +Y direction is up and +Z is out of the page. The force of gravity acts on the object in the –Y direction. Plot the X, Y, and Z components of the torque acting on the object and the angular momentum of the object from t = 0 s to t = 1 s. The reference point is the origin of the coordinate system. Use g = 9.8 m/s 2 and neglect air resistance. Make sure your plots clearly show: A. The values at t = 0 and t = 1 with correct units. B. Whether each graph is curved or straight. Y 0.5 kg X +3.0 m/s (0.0, 4.9, 0.0) m You can use this page for scratch work. We will not grade this page. See the next page for the graphs that you will be drawing. Name ________________________________________________________________________ 6 B-2 – Graphing – 24 Points (Continued) 0 ly ( ) t (s) lz ( ) lx ( ) 1.0 0 0 t (s) 1.0 0 0 t (s) 1.0 0 0 τy ( ) t (s) τz ( ) τx ( ) 1.0 0 0 t (s) 1.0 0 0 t (s) 1.0 0 Angular Momentum ComponentsTorque Components Name ________________________________________________________________________ 7 Problem C-1 (24 Points) * Two balls with masses m1 and m2 hang from ideal, massless strings of length r = 1.00 m. Initially, ball 1 is at rest a distance r above its lowest point and ball 2 is at rest at its lowest point (h = 0) as shown in Figure A. Ball 1 is released and is moving to the right at the instant before it hits ball 2 as shown in Figure B. In the instant after the elastic collision, ball 1 is moving to the left and ball 2 is moving to the right as shown in Figure C. m2 = 3.00 m1. What is the maximum height of each ball above h = 0 after the collision? You can assume the collision is one-dimensional and elastic. Neglect air resistance. m2 r m1 C r m2 r m1 A h = 0 m2 r m1 B r r h = 0 Maximum height of Ball #1 = ___________________________________ units ____ Maximum height of Ball #2 = ___________________________________ units ____ * Don’t forget to check A-8.