1. Physics of:
Motion

2. What is physics?
The branch of science that explains nature or our physical world.
The branch of science concerned with the study of properties and interactions of space, time, matter and energy.

3. The Language of Motion
In order to study motion we must first understand the language of motion.
You will recognize or know most of the terms used in the physics of motion however we must learn to use them in the right situation with the right meaning.

4. Motion Almost everyone moves from place to place during the day.
We do this in a variety of ways.
How do we describe motion? Is it walking or running. Is it speeding up or slowing down? Are we almost not moving or traveling at the speed of light?

5. Important Terms
If the technical term is considered a scalar quantity it means it has a magnitude (size) but no direction.
If the technical term is considered a vector quantity it means it has both magnitude and direction. An arrow over a letter symbolizes a vector quantity. (→)
You must also recognize the symbol Δ as delta and it means “change in”.

6. Distance
Measures the total length of a journey along every twist and turn of the path. It is a measured quantity – a quantitative observation.
Measured in metres (m)
Distance is a scalar quantity.

7. d=distance
di = initial distance
df = final distance
Δd = change in distance or distance interval
Calculation: Δd = df - di

8. Time
Describes when an event occurs, is measured in seconds, and is a scalar quantity.
Time is normally set to zero at the beginning of an experiment so initial time is taken as zero.

9. t = time
ti = initial time
tf = final time
Δt = change in time or time interval
Calculation: Δt = tf - ti

10. Position
Describes an object’s location as seen by an observer from a particular viewpoint (Earth’s surface).
Position is a vector quantity and is measured in metres.
Initial position in a lab is normally recorded as the reference position or origin (zero).

11. = position
= initial position
= final position

12. Displacement
Describes how much an object’s position has changed. However, if an object ends up back where it started it’s displacement is zero.
Displacement is a vector quantity and is measured in metres.
= displacement
Calculation:

13. Speed
Distance and time are two terms that are linked when we look at how fast we can travel.
Describes how fast something is moving.
Distance and time are measured to determine the speed, v, of an object.
Speed is a rate of motion, measured in m/s.

14. Velocity
Describes the speed and direction of motion; how fast an object’s position is changing.
Velocity is a vector quantity and it is measured in metres per second (m/s).

15. = velocity
= initial velocity = final velocity
= average velocity
= instantaneous velocity (velocity at a specific instant in time
= change in velocity
Calculation:

16. Acceleration
Describes how much an object’s velocity changes in a certain time.
Acceleration results from any change in velocity: speeding up, slowing down, changing direction, or a combination.
Acceleration is a vector quantity and is measured in metres per second in each second (m/s2)

17. = acceleration
= average acceleration
= instantaneous acceleration