Engineering Mechanics: Statics and Dynamics, 14th Edition

Engineering Mechanics: Statics and Dynamics, 14th Edition

Authors: Russell C. Hibbeler

ISBN-13: 978-0133915426

See our solution for Question 28FP from Chapter 2 from Hibbeler's Engineering Mechanics.

Problem 28FP

Chapter:
Problem:
Determine the projected component of the force along the line OA...

Step-by-Step Solution

Step 1

We are given the force $F = 650\;{\rm{N}}$.


We are asked to determine the projected component of the force along the line OA.


 
Step 2

The following is the diagram to calculate the projected component of the force.

Images


To find the unit vector we will use the formula,

\[\begin{array}{l} \vec u = \left( {\frac{{12}}{{13}}\hat i + \frac{5}{{13}}\hat j} \right)\\ \vec u = \left( {0.923\hat i + 0.385\hat j} \right) \end{array}\]
 
Step 3

To find the projected component of force we will use,

\[\vec F = F \cdot \vec u\]

On plugging the known values in the above relation, we get,

\[\begin{array}{l} \vec F = \left( {0\hat i + 650\;{\rm{N}}\hat j} \right) \cdot \left( {0.923\hat i + 0.385\hat j} \right)\\ \vec F = 250.25\;{\rm{N}} \end{array}\]

To find the projection of the force we will use the following relation,

\[{F_{OA}} = \vec F\vec u\]

On plugging the known values in the above relation, we get,

\[\begin{array}{l} {F_{OA}} = \left( {250.25\;{\rm{N}}} \right) \cdot \left( {0.923\hat i + 0.385\hat j} \right)\\ {F_{OA}} = \left( {230.9\hat i + 96.3\hat j} \right)\;{\rm{N}} \end{array}\]