This document describes motion and related concepts in physics. It defines motion as a change in the position or location of an object over time. It discusses how the study of motion is important in fields like physics, geology, cosmology and medicine. It also defines key terms like scalar and vector quantities, distance and displacement, speed and velocity, acceleration, equations of motion, and graphical representations of motion using distance-time and velocity-time graphs. Contact information is provided for the author.
3. DESCRIBING MOTION
Everything around us is moving in
one way or the other.
In fact stones, trees, roadways which seem to be
stationary also move with the earth's rotation.
Motion is a natural event that involves a change in
the position or location of an object with time.
4. DESCRIBING MOTION
Study of motion of objects is a very important aspect of
physics. Chemical reactions are possible only because of
movement and collision. Geologists use physics of waves to
study and measure the tectonic-plate motion and predict
earthquake. Cosmologists use this physics to study the
behavior of heavenly bodies and doctors use it to map the
flow of blood to check whether the arteries are blocked.
5. scalar quantity in physics is a physical quantity that can be
described by a single element of a number field such as a real
number, often accompanied by units of measurement.
A scalar is usually said to be a physical quantity that only has
magnitude and no other characteristics. This is in contrast to vectors,
tensors, etc. which are described by several numbers that
characterize their magnitude, direction, and so on.
DESCRIBING MOTION
6. a vector quantity is that has magnitude (or length) and
direction.
the velocity and acceleration of a moving object and the forces
acting on it can all be described with vectors. Many other physical
quantities can be usefully thought of as vectors.
DESCRIBING MOTION
8. Speed and Velocity
*Speed is the distance travelled by an object in
Unit time
*S.I. unit of speed is m/s or metre/second
*Average Speed
*Velocity is the displacement of an object in unit time
*S.I. unit of Velocity is m/s
Speed=distance travelled/time
Velocity=displacement/time
DESCRIBING MOTION
9. A displacement is a vector whose length is the shortest
distance from the initial to the final position of a point P. It
quantifies both the distance and direction of an imaginary
motion along a straight line from the initial position to the final
position of the point.
DESCRIBING MOTION
10. Acceleration, is the rate of change of velocity of an object with
respect to time.
* An object's acceleration is the net result of any and all forces
acting on the object, as described by Newton's Second Law.
*The SI unit for acceleration is metre per second squared (m s-2
).
*Accelerations are vector quantities.
Acceleration=
DESCRIBING MOTION
velocity
time
