Statics Week-1 2014

UNIT-1: Introduction

Fundamental Concepts

Idealizations

Three forces act on the ring. Since theseforces all meet at point, then for any forceanalysis, we can assume the ring to berepresented as a particle.

Steel is a common engineering material that does not deformvery much under load. Therefore, we can consider thisrailroad wheel to be a rigid body acted upon by theconcentrated force of the rail.

Unit-2: Vectors

This electric transmission tower is stabilized by cables that exert forces on thetower at their points of connection. In this chapter we will show how to expressthese forces as Cartesian vectors, and then determined their resultant

Content

• Scalars and vectors• Vector operations• Cartesian vectors• Position vectors• Force vector directed along a line• Dot product

Where to use vectors in engineering?

Using the parallelogram law the supportingforce F can be resolved into componentsacting along the u and v axes .

Exercises for Problem Solving of Vectors

Determine the magnitude and direction of the resultant force.

If FB = 2 kN and the resultant force acts along the positive u axis, determine the magnitude of the resultant force and the angle u.

Exercise of Addition of system of coplanar forces

The link in Fig. is subjected to two forces F1 and F2 . Determinethe magnitude and direction of the resultant force.

Projections in x,y,z directions of A

Position Vector

Exercise for positin vector section

Exercise of Cartesian vectors

Two forces act on the hook shown in Figure. Specify the magnitudeof F2 and its coordinate direction angles so that the resultant force FR

acts along the positive y axis and has a magnitude of 800 N.

Exercise for force directed along a line

The man pulls the cord with a force of 350 N. represent this force acting on the support of A as a cartesian vector and determine its directions

Exercise

The antenna tower is supported by three cables. If the forces of these cables acting on the antenna are FB = 520 N FC = 680 N FD = 560 N and determine the magnitude and coordinate direction angles of the resultantforce acting at A.

Unit-3: Equilibrium of a Particle

Content

• Condition for the equilibrium of a particle• FBD• Coplanar force systems• 3D force systems

Exercise-1

If cables BD and BC can withstand a maximumtensile force of 20 kN , determine the maximum mass of thegirder that can be suspended from cable AB so that neithercable will fail. The center of mass of the girder is located atpoint G.

Exercise-2

Determine the forces in cables AC and AB neededto hold the 20-kg ball D in equilibrium. Takeand d = 1 m.F = 300 N

Exercise-3

Determine the force acting along the axis of each of the three struts needed to support the 500-kg block.

Unit-4 Force System Resultants

Content

• Moment• Cross product• Moment of a force about a specified axis• Moment of a couple• Simplification of a force and couple system• Reduction of a simple distributed loading