Chapter 9, Problem 9.21P

2. 3. 4. clockwise from Four masses A, B, C and D revolve at equal radii and are equally spaced along a shaft. The mass B is 7 kg and the radii of C and D make angles of 90° and 240° respectively with the radius of B. Find the magnitude of the masses A, C and D and the angular position of A so that the system may be completely balanced. [Ans. 5 kg: 6 kg; 4.67 kg; 205° from mass B in anticlockwise direction] A rotating shaft carries four masses A, B, C and D which are radially attached to it. The mass centres are 30 mm, 38 mm, 40 mm and 35 mm respectively from the axis of rotation. The masses A, C and D are 7.5 kg. 5 kg and 4 kg respectively. The axial distances between the planes of rotation of A and B is 400 mm and between B and C is 500 mm. The masses A and C are at right angles to each other. Find for a complete balance, 1. the angles between the masses B and D from mass A, 2. the axial distance between the planes of rotation of C and D. 3. the magnitude of mass B. [Ans. 162.5%,…

1. Four masses A, B, C and D are attached to a shaft and revolve in the same plane. The masses are 12 kg. 10 kg. 18 kg and 15 kg respectively and their radii of rotations are 40 mm, 50 mm, 60 mm and 30 mm. The angular position of the masses B, C and D are 60°, 135° and 270 from the mass A. Find the magnitude and position of the balancing mass at a radius of 100 mm. [Ans. 7.56 kg: 87 clockwise from A]

3. The structure in Figure 3 is loaded by a horizontal force P = 2.4 kN at C. The roller at E is frictionless. Find the axial force N, the shear force V and the bending moment M at a section just above the pin B in the member ABC and illustrate their directions on a sketch of the segment AB. B P D A 65° 65° E all dimensions in meters Figure 3