Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001

15.3 EQUILLIBRIUM OF FORCES AND MOMENTS

· It is often necessary to solve problems using both sums of moments and forces. Indeed, both of these sums must be equal to zero for the body to be static.

· An example of a problem that has both forces and moments is given below, ([Hibbeler, 1992], prob 5-4, pg. )

[working model file]

· Try the problem below,

· Consider the pictures of both the hoists below, they are much like the examples that follow. The red dampers apply a force that is almost static to slow the lowering of the upper arms.

[picture]

· Lets consider another complex system to solve. In this case free body diagrams are beginning to become essential. ([Hibbeler, 1992], prob 5-44, pg. )

[working model file]

· Now, lets try a problem using vectors, ([Hibbeler, 1992], prob 5-83, pg. )

************************* Solution in Mathcad ***************************