THE UNIVERSITY OF BRITISH COLUMBIA 2013/2014 WINTER SESSION SESSIONAL EXAMINATIONS PHYSICS 170 MECHANICS I 7:30 pm to 8:30 pm, Wednesday, February 12, 2014 MARKS This exam counts for a total of 20 marks towards your Final Grade for the course. The exam consists of 2 questions each worth 20 marks. Write all work to be marked in the Answer Booklets provided. NUMERICAL ANSWERS You must give numerical answers correctly to three figures and with correct units to get any marks for your numerical answers. No marks are given 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 Midterm Exam: 7:30 pm to 8:30 pm, Wednesday, February 12, 2014 QUESTION 1 (20 marks) The diagram below shows a rectangular plate acted on by forces FA, FR, Fc and by a couple moment M=(6001- 700}+ 900k) N · m. P has coordinates x =3 m, y = 2 m. a) Draw a large, clear diagram for the plate showing the forces and the couple moment. b) The force and couple moment system is replaced by an equivalent resultant force FR acting at P and couple moment (MR)p · Express FR as a Cartesian vector. (3 marks) Express (MR)p as a Cartesian vector. (6 marks) c) Determine the magnitude of FR and its coordinate direction angles. (3 marks) d) Determine the magnitude of (MR)p and its coordinate direction angles. (3 marks) e) Do FR and (MR)p form a wrench? Explain. (2 marks) (3 marks) Z. FB= {800k} N M FA= {500i} N AV 1 P V B x 4 m y 6 m C Fc= {300j} N
PHYSICS 170 MECHANICS I Midterm Exam: 7:30 pm to 8:30 pm, Wednesday, February 12, 2014 QUESTION 2 (20 marks) The diagram below shows a rigid body pipe assembly acted on by a force and couple moment as shown and held in equilibrium by smooth journal bearings at A, B and C. The bearings are in proper alignment and only exert force reactions on the rigid body. The weight of the rigid body may be neglected. a) Draw a large, clear free-body diagram for the rigid body. (4 marks) b) Determine Cartesian component force equations of equilibrium for the rigid body. (4 marks) c) Determine Cartesian component moment equations of equilibrium for the rigid body. (8 marks) d) Solve the Cartesian component equations of equilibrium to determine the Cartesian components of the force reactions at A, B and C. (4 marks) N- - 450 N C A 300 N · m 0.6 m 45° 0.4 m X 0.8 m 0.4 m B y