ASSIGNMENT ONE 1. 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. A rotating shaft is to carry four discs, A, B, C and D, whose masses are 15 kg, 25 kg, 20 kg and 18 kg respectively; they are to be spaced at intervals of 300 mm, 375 mm and 225 mm along the shaft. The centres of mass A, B and C are at 36 mm, 12 mm and 18 mm respectively from their axes of rotation. a. The three discs A, B and C are first attached to the shaft, at the spacing specified above and with their centres of mass in positions which give static balance. Find the relative angular positions of their centres of mass. b. The disc D is then attached to the shaft in such a position as to nullify the outof-balance couple, when the reference plane passes through A. Find the eccentricity of the centre of mass of D and its angular position relative to that of A. 2. 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. 3. The rocker of a crank-rocker linkage is to have a length of 500 mm and swing through a total angle of 45° with a time ratio of 1.25. Determine a suitable set of dimensions for π1 , π2 πππ π3 . ASSIGNMENT TWO 1. If link CD shown in Figure 1 has an angular velocity of ππΆπ· = 6 πππ/π , determine the velocity and acceleration of point E on link BC and the angular velocity and angular acceleration of link AB at the instant shown. Figure 1 2. At the instant shown in Figure 2 rod AB has an angular velocity ππ΄π΅ = 4 rad/s and an angular acceleration πΌπΆπ· = 2 πππ/π 2 . Determine the angular velocity and angular acceleration of rod CD at this instant. The collar at C is pin connected to CD and slides freely along AB. Figure 2 3. The"quick-return" mechanism shown in Figure 3 consists of a crank AB, slider block B, and slotted link CD. If the crank has the angular motion shown, determine the angular motion of the slotted link at this instant. Figure 3 ASSIGNMENT THREE 1. In the epicyclic gear train shown in Figure 4, shaft A is stationary. If gear 2 rotates at 800 rpm cw. What are the speed and direction of rotation of shaft B? Figure 4 2. Find the speed and direction of rotation of gear 8 in Figure 5. What is the speed ratio of the train? Figure 5