Engineering Mechanics Assignment Sheet – 3 Friction & Forces in Space Module – 3 Assignment Question 1. A block having mass 40 Kg and dimension as shown in Fig, is resting on a flat surface. The coefficient of static friction between the block and the surface is 0.3. Find the magnitude of tension T required to cause motion. Also describe in what manner motion would take place if: a) h = 15 cm b) h = 22 cm 2. A 100 wedge is to be forced under end B of 6 Kg rod AB. If µs = 0.4 between the wedge and rod and 0.2 between the wedge & the floor. Determine the smallest force P require to raise end B of rod. 3. There block are placed on the surface one above the other as shown in fig. The static coefficient between the blocks and block C and surface is also shown. Determine the maximum value of P that can be applied before any Slipping take place. [Ans: 25.5 N] [May 08] Engineering Mechanics Assignment Sheet – 3 Friction & Forces in Space Module – 3 4. A plate foundation is subjected to five vertical forces as shown in fig. Replace these five forces by means of single vertical forces and find the point of replacement. 5. Force F = (3i – 4j + 12k) N acts at point A (1, -2, 3). Find i) Moment of force about origin ii) Moment of force about point B(2,1,2)m [Ans: MFO = (-12i – 3j -2k) Nm, MFB= (-32i + 15j + 13k) NM] 6. Determine the tension in cable AB, AC & A. If weight of cylinder is 160 Kg.