KINEMATICS
Kinematics is a branch of mechanics. It is the science of describing the motion of
objects using words, diagrams, numbers, graphs, and equations.
Its goal is to describe and ultimately explain the motion of real-world objects.
The mathematical quantities that are used to described the motion of objects can be
divided into two categories; scalar and vector.
Note:
Motion is the action of changing position or location. An object is in motion if its
position changes in relation to some fixed object during a given time
Scalar and Vector Quantities
SCALAR:
It has magnitude, a numerical value and unit of quantity. It has a value but no
direction.
Distance, Speed, Mass, Energy, Density, Power, Length, Area, Volume, Time,
Temperature, Work
Symbol Names of Scalars Example
d Distance 30 m
v Speed 50 m/s
t Time 15 s
E Energy 2000 cal
VECTOR:
It has both magnitude and direction.
Displacement, Velocity, Weight, Acceleration, Force, Impulse, Pressure,
Momentum, Gravity, Drag
Symbol Names of Vectors Example
d Displacement 30 m North
v Velocity 50 m/s West
F Force 100 lb up
a Acceleration 12 m/s2 down
, Distance vs. Displacement:
Distance and displacement are two quantities that may seem to mean the same
thing yet have distinctly different definition and meanings.
Distance (Scalar)
Refers to “how much ground an object has covered” during its motion
length of the actual paths traveled
Displacement (Vector)
Refers to “how far out of place an object is”
objects change in position considering its staring and final position
Speed vs. Velocity:
Speed (Scalar):
Refers to “how fast an object is moving”
Distance covered per unit of time
A fast-moving object has a high speed and covers a relatively large distance in a
short amount of time
A slow-moving object that has a low speed; it covers a relatively small amount of
distance in the same amount of time
An object with no movement at all has a zero speed
Velocity (Vector):
Refers to the “the rate at which object changes its position”
Speed + Direction
Even if the object is slowing down and the magnitude of velocity is decreasing, its
direction would still be the same as the direction in the object is moving
Acceleration:
The rate at which an object changes its velocity
An object is accelerating if it is changing its velocity
A change in direction (from East to North-East)
A change in both speed and direction (from 34 km/h East to 12 km/h West)
A change in speed, the magnitude of the velocity (from 34 km/h to 67 km/h)
If an object is not changing its velocity, then the object is not accelerating
REPRESENTING VECTORS:
Kinematics is a branch of mechanics. It is the science of describing the motion of
objects using words, diagrams, numbers, graphs, and equations.
Its goal is to describe and ultimately explain the motion of real-world objects.
The mathematical quantities that are used to described the motion of objects can be
divided into two categories; scalar and vector.
Note:
Motion is the action of changing position or location. An object is in motion if its
position changes in relation to some fixed object during a given time
Scalar and Vector Quantities
SCALAR:
It has magnitude, a numerical value and unit of quantity. It has a value but no
direction.
Distance, Speed, Mass, Energy, Density, Power, Length, Area, Volume, Time,
Temperature, Work
Symbol Names of Scalars Example
d Distance 30 m
v Speed 50 m/s
t Time 15 s
E Energy 2000 cal
VECTOR:
It has both magnitude and direction.
Displacement, Velocity, Weight, Acceleration, Force, Impulse, Pressure,
Momentum, Gravity, Drag
Symbol Names of Vectors Example
d Displacement 30 m North
v Velocity 50 m/s West
F Force 100 lb up
a Acceleration 12 m/s2 down
, Distance vs. Displacement:
Distance and displacement are two quantities that may seem to mean the same
thing yet have distinctly different definition and meanings.
Distance (Scalar)
Refers to “how much ground an object has covered” during its motion
length of the actual paths traveled
Displacement (Vector)
Refers to “how far out of place an object is”
objects change in position considering its staring and final position
Speed vs. Velocity:
Speed (Scalar):
Refers to “how fast an object is moving”
Distance covered per unit of time
A fast-moving object has a high speed and covers a relatively large distance in a
short amount of time
A slow-moving object that has a low speed; it covers a relatively small amount of
distance in the same amount of time
An object with no movement at all has a zero speed
Velocity (Vector):
Refers to the “the rate at which object changes its position”
Speed + Direction
Even if the object is slowing down and the magnitude of velocity is decreasing, its
direction would still be the same as the direction in the object is moving
Acceleration:
The rate at which an object changes its velocity
An object is accelerating if it is changing its velocity
A change in direction (from East to North-East)
A change in both speed and direction (from 34 km/h East to 12 km/h West)
A change in speed, the magnitude of the velocity (from 34 km/h to 67 km/h)
If an object is not changing its velocity, then the object is not accelerating
REPRESENTING VECTORS:
