THE UNIVERSITY OF BRITISH COLUMBIA 2015/2016 WINTER SESSION SESSIONAL EXAMINATIONS PHYSICS 170 MECHANICS I 12 noon to 2:30 pm, Friday, April 22, 2016 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, Friday, April 22, 2016 QUESTION 1 The diagram below shows a rigid body held in equilibrium by journal bearings at A, B and C. The body is acted upon by a force F as shown and by a couple moment M = (2007 - 300] + 400k) N ·m . The magnitude of F is 100 N. The journal bearings are smooth and only exert force reactions on the rigid body. The weight of the body may be neglected. a) Draw a large, clear free-body diagram for the body. b) Determine Cartesian component force equations of equilibrium for the body. c) Determine Cartesian component moment equations of equilibrium for the body. d) Determine numerical values for the Cartesian components of the reactions at A, B and C. The z-component of the reaction at A is 200 N. M Z C A 2 m 2 m B x 30° -1 m- 0.75 m 60° y F
PHYSICS 170 MECHANICS I Final Exam: 12 noon to 2:30 pm, Friday, April 22, 2016 QUESTION 2 In the diagram below, block A is on a horizontal surface and block B is on the sloped surface of block A. The mass of A is 10 kg. The mass of B is 5 kg. The sloped surface of A makes an angle of 40° with the horizontal. Friction between A and the horizontal surface and between A and B may be neglected. The blocks are released from rest. This Question refers to the situation when A and B are in motion. Block A accelerates to the left. The magnitude of the acceleration of B relative to A is 7.8391 m/s2. a) Draw a large, clear free-body diagram for each block. b) Determine Cartesian component equations of motion for each block. c) Determine numerical values for the normal force between A and B, the normal force between the horizontal surface and A, the acceleration of A, and the acceleration of B.