PHYSICS 170 MECHANICS 1: Final Exam: 3:30 PM to 6:00 PM, Saturday, Dec. 16, 2017 PLEASE DO NOT READ PAST THIS COVER SHEET UNTIL INSTRUCTED TO START MARKS This exam counts for a total of 50 marks towards your Final Grade for the course. The exam consists of 4 questions for a total of 80 marks. The first question is worth 25 marks, the second is worth 20 marks, the third is worth 15 marks and the fourth is worth 20 marks. Write all work to be marked in the Answer Booklets provided, and use both sides of the pages. Please ensure that your name and student number are written clearly on your Answer Booklet(s). 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 printed or reduced material, or sample problems, or solutions to sample problems. Put your name and student number on your Information Sheet and sign it. You must hand in your Information Sheet with your Answer Booklet(s) in order for your exam to be marked.
PHYSICS 170 MECHANICS 1: Final Exam: 3:30 PM to 6:00 PM, Saturday, Dec. 16, 2017 QUESTION 1 (25 marks) The diagram below shows a rigid body ABD which supports a 50 lb sign, and which is itself supported in equilibrium by two cables (BC and DE) and at A by a smooth collar. The weight of the sign acts at its center of gravity, G, which has coordinates (x, y, z) = (0.5, 2, -1) ft. The weight of ABD can be neglected. In the following, ABDG refers to ABD together with the supported sign: ABDG is to be considered a single rigid body. a) Draw a large, clear free-body diagram for ABDG. (7 marks) b) Determine Cartesian component equations of equilibrium for ABDG. (15 marks) c) Determine numerical values for the Cartesian components of reaction at A and the tensions in the cables. (3 marks) Z. 4 ft 3 ft 2 ft 1 E A 2 ft B 3 ft 2 ft x 2 ft D 1 1 ft G y 2.5 ft 1 ft 2.5 ft
PHYSICS 170 MECHANICS 1: Final Exam: 3:30 PM to 6:00 PM, Saturday, Dec. 16, 2017 QUESTION 2 (20 Marks) In the diagram below, the 0.5 kg particle, C, is forced to move along the vertical slotted path r=(0.50) m, where 0 is in radians. The angular position of the arm is 0 = (0.5t2 ) rad, where t is in seconds, and the instant shown is t = 2 s. The rod exerts a force F on C and the slot exerts a normal force N on C. The particle is in contact with only one edge of the rod