This document defines and discusses key concepts related to motion, including reference points, distance, displacement, scalar and vector quantities. It notes that motion depends on the choice of reference point. Distance is the length of the path traveled between two positions, while displacement is a vector quantity referring to the straight line distance between two positions. Scalar quantities only have magnitude, while vector quantities have both magnitude and direction. Examples of each are provided.

1. MotionJEROME A. BIGAEL
LEYTE PROGRESSIVE HIGH SCHOOL

2.  In July 1969, Neil Armstrong
(1930-2012) said, “One step of
man, one giant leap for
mankind.” From that time,
great leaps and progress in
science and technology were
made.
 Wireless communication,
genetic engineering, and space
explorations are just some of
some mankind’s achievement.

3. Armstrong was able to leap on the
surface of the moon at a height which
he could not have reached on Earth
because of gravity.
As you know, the gravitational force
on the moon is less compared to that
on Earth.

4. Definition of Motion
 Reference points are very important in describing the motion of
objects.
It is a fixed point and does not move so that the position of an object is
described by the coordinate with respect to the reference point.
 If you are standing still, can you say you are in motion?
The answer depend on the reference point.
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5. If you ask that question to a classmate who is in the
same room, he or she might tell you that you are not
moving.
But if you ask an observer from a satellite orbiting
Earth, he or she might say “yes you are moving”.
Since Earth is rotating about it’s axis, the observer from
an orbiting satellite will tell you that you are moving.
Thus motion is a change in position with
respect to a reference point and time.

6. The study of motion can be divided into 2
Kinematics and Dynamics
Kinematics = describes motion in terms of
displacement.
Dynamics = relates force and motion.
Translation is the term used in physics for motion in a
straight line.

7. In our study of translation, we shall
consider the origin of the Cartesian
coordinate as start of motion.
Position, velocity, and acceleration to
the right of the origin are considered
positive.
On the other hand, position, velocity,
and acceleration to the left of the
origin shall be considered negative.
*on the next section we will consider
motion along the horizontal axis.

8. Distance versus Displacement
Quantities that are used to describe
motion of an object can either be scalar or
vector.
Scalar quantities are those that can be
described completely by their magnitudes
and appropriate units.

9. What is a magnitude?
the meaning of
magnitude is 'size' or
'quantity'.

10. Vector quantity are those that are
completely described by their magnitudes,
appropriate units, and directions.

11. A distinction has to be made between
distance and displacement.
Distance is scalar.
Distance d travelled by an object is the
length of the path taken by an object
from its initial to its final position.

12. Displacement d is a vector with direction
pointing from the initial to the final
position and magnitude or length equal
to the straight line distance from the
initial to final position.

13. Quiz
1. A physical quantity which has direction as
well as magnitude is known as a:
(a) force
(b) vector
(c) scalar
(d) weight

14. 2. Which of the following is not a scalar quantity?
(a) velocity
(b) potential energy
(c) work
(d) kinetic energy

15. 3. Which of the following is not a vector quantity?
(a) displacement
(b) density
(c) velocity
(d) acceleration

16. 4. Which of the following statements is false?
(a) Scalar quantities have size or magnitude only
(b) Vector quantities have both magnitude and
direction
(c) Mass, length and time are all scalar quantities
(d) Distance, velocity and acceleration are all vector
quantities

17. 5. Identify the following quantities as scalar or vector:
the mass of an object, the number of leaves on a
tree, wind velocity.
A. Vector, scalar, scalar
B. Vector, scalar, vector
C. Scalar, scalar, vector
D. Scalar, vector, vector

18. Answer key:
1.b
2.a
3.b
4.d
5. C