THE UNIVERSITY OF BRITISH COLUMBIA 2016/2017 WINTER SESSION SESSIONAL EXAMINATIONS PHYSICS 170 MECHANICS I 12 noon to 2:30 pm, Monday, April 24, 2017 MARKS This exam counts for a total of 50 marks towards your Final Grade for the course. The exam consists of 4 questions. All questions are worth the same number of marks. Write all work to be marked in the Answer Booklets provided. NUMERICAL ANSWERS You must write numerical answers correctly to three significant figures and with correct units to get any marks for your numerical answers. No marks are awarded for correctly solving incorrect equations. CALCULATOR You may use a graphing calculator. INFORMATION SHEET You may consult one 8 1/2 inch by 11 inch hand-written double-sided Information Sheet. Your Information Sheet must not contain any sample problems or solutions to sample problems. Put your name and student number on your Information Sheet. You must hand in your Information Sheet with your Answer Booklet in order for your exam to be marked.
PHYSICS 170 MECHANICS I Final Exam: 12 noon to 2:30 pm, Monday, April 24, 2017 QUESTION 1 The diagram below shows a rigid body acted on by a 400 N force in the direction shown and by a couple moment M = (-600] + 720k)N·m where ] and k are the usual Cartesian unit vectors. The body is held in equilibrium by cables attached to B and to C and by a ball-and-socket joint at D. The weight of the rigid body may be neglected. a) Draw a large, clear free-body diagram for the rigid body. b) Determine Cartesian component force equations of equilibrium for the rigid body. c) Determine Cartesian component moment equations of equilibrium for the rigid body. d) Determine numerical values for the forces exerted by the cables and the Cartesian components of reaction at D. B 3 m 6 m C 0 2 m D A 30° 400 N
PHYSICS 170 MECHANICS I Final Exam: 12 noon to 2:30 pm, Monday, April 24, 2017 QUESTION 2 In the diagram below, block A is on a smooth horizontal surface and block B is on the smooth sloped surface of block A. The mass of A is 5 kg. The mass of B is 10 kg. The angle 0 = 20°. Friction between A and the horizontal surface and between A and B may be neglected. A force P of magnitude 150 N acts on B. The magnitude of the acceleration of B relative to A is 3.2657 m/s2. a) Draw large, clear free-body diagrams for the blocks. b) Determine equations of motion for each block. c) Determine numerical values for the acceleration of A, the normal force between A and B, and the normal force between A and the horizontal surface. P B A 0