# Introduction To Statics - Teacher's Guide

Helen L. Plants and Wallace S. Venable

West Publishing Company, St. Paul, 1975

# Appendix I - Objectives for Introduction to Statics

All objectives are to be met completely correctly in four out of five trials.

## I. Fundamental skills

#### A. Vector mathematics

1. Given a vector and two lines the student shall find its components along the lines,

a. when the lines are orthogonal.

b. when the lines are nonorthogonal.

He shall solve such problems,

a. using vector algebra.

b. graphically.

2. Given a right handed coordinate system the student shall

a. resolve a given vector into orthogonal components and represent it as

i. a magnitude times a unit vector.

ii. components.

iii. an arrow on a drawing.

b. find the position vector of one given point with respect to another.

3. Given expressions for two vectors A and B and a scalar k the student shall compute

c. A + B

d. A - B

e. kA

4. Given a vector V which passes through a point P1, the student shall compute the moment of V about

a. a given point P2

b. a line passing through P2 and a third given point P3

5. Given a system of vectors and points the student shall compute the moment of the system of vectors about a point and a line.

#### B. Force Systems

1. Given a couple expressed as two forces the student shall compute its moment.

2. Given a force at point P1 the student shall resolve it into a couple and a force at some other given point P2.

3. Given a two dimensional force system the student shall find the resultant force and locate its line of action.

4. Given a three dimensional force system the student shall reduce the system to a force (at a specified point) and a couple.

5. Given a distributed load the student shall find its resultant and locate its center of pressure.

6. Given a body the student shall locate its center of mass.

#### C. Free Body Diagrams

1. Given a system of rigid bodies the student shall

a. draw a free body diagram of a designated member.

b. draw a free body diagram of an adjacent member showing the reversal of forces at the joint.

c. draw a free body diagram of the complete system.

## II. Properties of Areas

#### A. Given a plane figure whose boundary equations are given the student shall

1. compute the first moment of the area about the x axis.

2. locate the centroid of the area.

3. compute the moment of inertia

a. about a centroidal axis in the plane.

b. about a coordinate axis in the plane.

#### B. Given a plane figure made up of circular, rectangular and triangular elements the student shall

1. compute the first moment of the composite figure about a specified axis.

2. locate its centroid.

3. compute its moment of inertia about a specified axis in the plane of the figure.

4. compute its moment of inertia about an axis through its centroid.

## III. Equilibrium

#### E. Given a pin jointed truss, the student shall find the force in a designated member using

1. the method of joints.

2. the method of sections.