MAE-2103 Engineering Mechanics I: Practice Exam #1
1.
Three forces are concurrent at point A.
magnitude 6 N and is directed along

F1 =<2,
û =<-0.8,
3, 4> N,

F2 has
0.6, 0.0>, and

F3
has
o
magnitude 12N, lies in the x-z plane, and is 30 from the positive z-axis. Find
the resultant of these three forces.

r =<-2, -4, 4> m.
2.
Find the direction cosine angles of the vector
3.
Two forces act at point O as shown. F1=26 N and F2=10 N. Find the force
P and the angle  for equilibrium.
4.
Find the vector cross product of P=<-1, 0, 3> and Q=<4, -2, 2>.
5.
A tripod with legs AB, AC, and AD supports an unknown weight, P at
point A. Knowing that the compressive force in member AB is 70 N,
find the compressive forces in AC and AD.
R. Gist
1
Ver. A, Rev. 3
MAE-2103 Engineering Mechanics I: Practice Exam #1
6.
The plate is supported by a rope, AB. Tension in rope AB is 12 N. Find
the moment vector about the origin due to this tension.
7.
How much of moment
8.
Two equal forces which lie in the x-y plane act in opposite directions on the
wheel, also in the x-y plane. The radius of the wheel is 0.12 m. Find the
resulting couple moment due to these forces. F1=24 N and acts at 45o above
horizontal and to the right, and F2 is equal but opposite to F1.
9.

M =<20,
30, -40> N·m is in the direction
û =<-0.8, 0.6, 0>?

How much of the moment vector is perpendicular to û ? What is the angle between M and û ?

FA
=<24, 36, 0> N and
point A located at

rA =<0,

FB =<0,
0, -10> N.

FA acts at
2, 0> m (with respect to the origin), and


FB acts at point B located at rB =<3,
0, 0> m. Replace these two
forces with an equivalent system of one force vector and one moment
vector acting at origin.
R. Gist
2
Ver. A, Rev. 3