Engineering Mechanics Questions

Faculty of Engineering Department of Mining Engineering Engineeing Mechanics Instructor: Engr. Naseer Kakar Date: 18-01-2014 Submitted By: Ghulam Mehdi CMS ID# 23101 ----------------------------------------------------------------------------------------------------------------Q.No#01: Find the center of gravity of a semicircular section havingouter and inner diameters of 200 mm and 160 mm respectively as shown in fig?

Ans: 57.5 mmQ.No#02: A semicircular area is removed from a trapezium as shownin fig. Determine the position of the center of gravity?

Q.No#03:Find the center of gravity of an unequal angle section 10cm x 16 cm x 2 cm?

Ans: 5.67 mm and 2.67 mmQ.No#04:Find the center of gravity of T section with flange 150 mmx 10 mm and web also 150 mm x 10 mm?

Ans: 115 mmQ.N0#05:A semicircles of 90 mm radius is cut out from a

Engineering Mechanics 1 Lec: Engg. Naseer Kakar

trapezium as shown in fig. Find the position of the center ofgravity?

Center of the gravity = 69.1 mmQ.No#06:Find the centroid of an unequal angle section 100 mm x80 mm x 20mm.

Result x = 25 mm , y = 35 mQ.No#07: A body of weight 6 lb rests on a horizontal table and thecoefficient of friction between the two surfaces is 0.32.What horizontal force will be required to start the bodymoving? Ans: 1.92 lbsQ.No#08: A block of wood weighing 3 lb. rests on a horizontaltable. A horizontal force 1.25 lb. is just sufficient tocause it to slide. Find the coefficient of friction for thetwo surfaces and the angle of friction ?Ans: 0.42 & 22.6ºQ.No#09: A block having a mass of 220 Kg is resting on a woodenTable.What is the minimum force necessary to impartmotion to the block when the coefficient of frictionbetween the block and the table is 0.25?Ans:539 NQ.No#10:A body of mass 100 Kg rests on horizontal plane theco efficient of friction between body and the plane 0.40. Findthe work done in moving the body through a distance of 20 malong the plane.?Ans:Resultant weight = 748.8 NQ.N0#11: A horse exerts a pull of 3 KN just to move a carriagehaving a mass of 800 kg. Determine the co efficient of frictionbetween the wheel and the ground ?Take g = 10 m/sec²


Ans: Result co efficient of friction = 0.375Q.No#12:Determine the tension in cables AB and AD forequilibrium of the 250kg mass?

Q.No#13: Determine the moment of the force about point“O” for following diagram?

(a) Result: - Moment = 200N.m Direction =clock wise(b) Resultant Moment = 229.282 lb.ft Direction =clock wise

Q.No#14: Determine the moment of the force 800 N acting on theframe about points A, B, C and D?


Result: MA=2000 N.m clock wise Or MA = + 200 N.m , MB= 1200 N.m clock wise Or MB = + 1200 N.m ,Mc = OMD =. 400 N.m anti clock wise MD= - 400N.mQ.No#15: A 200 N force acts on the bracket as shown determine the

moment of force about “A”?

Q.No#16: Find the moment of the force about “O” as shown inDiagram?

Q.No#17: Determine the resultant moment of four forces acting onthe rod about “O” as shown is diagram?

Ans: 333.92 N m clock wiseQ.No#18: The Force F acts at the end of angle bracket shown in fig.Determine the resultant moment at point “O”?


Ans : 98.56 CWQ.No#19: A force of 40N is applied to the wrench. Determent themoment at point “O”?

Ans: 7.107 CWQ.No#20: The wrench is used to loosen the bolt. Determine themoment of each force about the bolt’s axis passingthrough point O?

(Ans: 24.1 N-m, 14.5 N-m)Q.No#21: Determine the moment of each of the three forces aboutpoint A?

Q.No#22: Determine the moment about point A of each of the threeforces


Ans: 600 N-m, 1.12 KN-m, 518 N-mQ.No#23: Calculate the moment of force 250 N on the handle ofmonkey wrench?

Q.No#24: Calculate the magnitude of moment about base point O?

Q.No#25: Determine the moment of couple acting on themoment shown?

…………………...With Best Luck…………………….Regards: Mehdi Shaheen
