ENGINEERING MECHANICS (Part 1)
Content:
1. Branches of Mechanics
2. Vector and Scalar Quantities
3. Resultant of two or more vector
4. Forces in equilibrium
5. Rectilinear motion
6. Free fall
7. Curvilinear motion
8. Newton’s law of motion
9. Friction
Engineering Mechanics is the branch of physical science
that deals with the study of bodies and systems of and
the forces acting on them.
Branches of Mechanics
1. Statics : deals with bodies in the state of rest
2. Dynamics : deals with bodies in motion
a. Kinematics: study of motion without reference
to the forces that causes motion
b. Kinetics: study of motion with reference to
the forces that causes motion
Vector and Scalar Quantities
Scalar quantity : a physical quantity, which has
magnitude only
Example: temperature, height, mass, age, speed,
distance, etc.
Vector quantity : a physical quantity which has both
magnitude and direction
Resultant of two or more vectors
For parallel vectors:
For vectors parallel horizontally:
R=F1± F2± F3± … ..± Fn
For vectors parallel horizontally:
R=F1± F2± F3± … ..± Fn
For Perpendicular vectors:
R=
√
(F1)2+(F2)2
Vectors acting at an angle other than 90º
Parallelogram Method:
R=
√
(F1)2+(F2)2−2F1F2cos θ
Component method:
R=
√
(
∑Fx
)
2+
(
∑Fy
)
2
θ=arctan
(
∑Fy
∑Fx
)
FORCES OF EQUILIBRIUM
TYPES OF EQUILIBRIUM:
Static equilibrium: is the condition of a body at rest
and remains at rest under the action of concurrent
forces.
Translational Equilibrium: is the condition of a body in
motion with constant motion
Condition of Equilibrium:
1. The vector sum of all forces acting on the body
must be equal to zero.
∑Fx=0
∑Fy=0
2. The sum of all torques acting on a body must be
equal to zero.
1 --- GEAS MECHANICS Prepared By EJBR
