Revision - Tutorial Questions 1. For the framework given below in
Transcription
Revision - Tutorial Questions 1. For the framework given below in
Revision - Tutorial Questions 1. For the framework given below in Fig. 1 determine the magnitude of the force in each member and state whether each is a tie or a strut. (Note that it is not usual to label the framework for you.) Answers R1= 2.75kN R2= 3.25kN All of the following found by measurement: hb = 3.75kN (strut) ch = 1.9kN (tie) fd = 1.6kN (tie) ef = 3.2kN (strut) ag = 2kN (strut) fg = 0.85kN (tie) gh = 0.3kN (tie) 2. Use the method of resolution at joints to verify the forces in the members that make up the top right hand joint of Fig. 1. 2kN 3kN A E R1 All members are 1m G F B H D 1kN Fig. 1 C R2 Answers hb = -3.75kN hg = 0.286 kN ga = -2.018 kN 3. For the pin jointed frame shown in Fig. 2 solve all the forces and reactions in the frame stating which members are tie and which are struts. The length of all vertical and horizontal members are 3m. A F E D G C 15kN H B 30kN Answers (These have not been verified by me) R1=25kN R2=20kN ha = 35.5kN (strut) bh = 25kN (tie) ed = 20kN (tie) ea = 29kN (strut) cg = 25kN (tie) gf = 7.07kN (strut) fa = 20kN (strut) ef = 20kN (tie) gh = 30kN (tie) 4. A load of mass 1350 kg lies on a gradient inclined at 60 o to the horizontal. For static friction μ = 0.5, for kinetic friction μ 0.4. Calculate: (a) the pull parallel to the gradient required to prevent the load sliding down; (b) the pull required to pull the load up the gradient at constant speed. (8.15 kN; 14.1 kN) 5. A body of mass m on a rough plane inclined at 20o to the horizontal is moved steadily up the plane by a force of 200 N applied upward and parallel to the plane. When the force is reduced to 75 N, the body slides steadily downwards. Determine the values of m and μ. (41 kg; 0.17) 6. For the loaded beam shown below produce neat sketches/drawings of the shear force and bending moments. x 10 kN 20 kN UDL = 15 kN/m 1.5 A B 2m R1 C D 2m E 0.5 m R2 7. Determine the resultant out of balance force at the centre of rotation 'O', when the system shown below rotates at 10 rev/min and state its direction. What value of balance weight would be required at 1m radius and where should it be placed? (55.94N; 51kg 12o to vertical) 8. Calculate the second moment of area for the section shown below about an axis X-X through the centroid. (Centroid 33.7mm from top; I = 3.19 x 106mm4) 9. A load of 8 t is to be raised with a uniform acceleration of 1.1 m/s 2 by means of a light cable passing over a hoist drum of 2 m diameter. The drum has a mass of 1 t and a radius of gyration of 750 mm. Find the torque required at the drum if friction is neglected. (87.8 kN)