Solutions Manual
Engineering Mechanics: Dynamics
2nd Edition
Gary L. Gray
The Pennsylvania State University
Francesco Costanzo
The Pennsylvania State University
Michael E. Plesha
University of Wisconsin–Madison
Version: May 12, 2012
Dynamics 2e 3
Important Information about
this Solutions Manual
often to obtain the most up-to-date version. In particular, as of December 16, 2009, please note the following:
_The solutions for Chapters 1, 2, and 4–9 have been accuracy checked and are in their final form.
_
The solutions for Chapter 3 have been accuracy checked and should be error free. We will be adding
some additional detail to these solutions in the coming weeks.
_
The solutions for Chapter 10 are a work in progress. The solutions for the first 29 problems in the
We welcome your input.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
4Solutions Manual
Accuracy of Numbers in Calculations
Throughout this book, we will generally assume that the data given for problems is accurate to three significant
digits. When calculations are performed, intermediate results are stored in the memory of a calculator or
computer using the full precision these machines offer. However, when these intermediate results are reported
significant digits.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
Dynamics 2e 5
Chapter 1 Solutions
Problem 1.1
Determine
.rB=A/x
and
.rB=A/y
, the
x
and
y
components of the vector
ErB=A
, so as to be able to write
ErB=A D.rB=A/xO{C.rB=A/yO|.
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permission of McGraw-Hill, is prohibited.
6Solutions Manual
Problem 1.2
If the positive direction of line `is from Dto C, find the component of the vector ErB=A along `.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
Dynamics 2e 7
Problem 1.3
Find the components of ErB=A along the pand qaxes.
Solution
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permission of McGraw-Hill, is prohibited.
8Solutions Manual
Problem 1.4
Determine expressions for the vector
ErB=A
using both the
xy
and the
pq
coordinate systems. Next,
determine
jErB=Aj
, the magnitude of
ErB=A
, using both the
xy
and the
pq
representations and establish
whether or not the two values for jErB=Ajare equal to each other.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
10 Solutions Manual
Problem 1.5
Suppose that you were to compute the quantities
ˇ
ˇErB=Aˇ
ˇxy
and
ˇ
ˇErB=Aˇ
ˇpq
, that is, the magnitude of the
vector
ErB=A
computed using the
xy
and
pq
frames, respectively. Do you expect these two scalar values to
be the same or different? Why?
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.