March 2010

Problem
If tan x = 1/3 and tan y = 1/2, what is the value of tan (x + y) and tan (x - y)?
 

Problem 002
Compute the x and y components of each of the four forces shown in Fig. P-002.
 

Problem 001
Problem Determine the x and y components of the forces shown below in Fig P-001.
 

Problem 654
For the beam in Fig. P-654, find the value of EIδ at 2 ft from R₂. (Hint: Draw the reference tangent to the elastic curve at R₂.)
 

Problem 653
Compute the midspan value of EIδ for the beam shown in Fig. P-653. (Hint: Draw the M diagram by parts, starting from midspan toward the ends. Also take advantage of symmetry to note that the tangent drawn to the elastic curve at midspan is horizontal.)
 

The deflection δ at some point B of a simply supported beam can be obtained by the following steps:
 

Forces acting at some angle from the the coordinate axes can be resolved into mutually perpendicular forces called components. The component of a force parallel to the x-axis is called the x-component, parallel to y-axis the y-component, and so on.
 

Coplanar Parallel Force System
Parallel forces can be in the same or in opposite directions. The sign of the direction can be chosen arbitrarily, meaning, taking one direction as positive makes the opposite direction negative. The complete definition of the resultant is according to its magnitude, direction, and line of action.
 

Resultant of a force system is a force or a couple that will have the same effect to the body, both in translation and rotation, if all the forces are removed and replaced by the resultant.