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.