Physics for 9th grade, chapter 2 (edited)

1. Photo taken by
Rasha Alkhateeb
Jubilee School

10. Speed vs. Velocity
* Speed is a scalar (how fast something is
moving regardless of its direction).
Ex: v = 20 mps
* Speed is the magnitude of velocity.
* Velocity is a combination of speed and
direction. Ex: v = 20 mps, at 15 south of west
* The symbol for speed is v.
* The symbol for velocity is type written in
bold: (v) or hand written with an arrow: v

13. Mass vs. Weight
Mass
• Scalar (no direction)
• Measures the amount of matter in an object
Weight
• Vector (points toward center of Earth)
• Force of gravity on an object
& On the moon!!!
your mass would be the same, but the
magnitude of your weight would be less.

14. Some Physics Quantities
Scalars --------------------------- Vectors
• Distance ----------------------- Displacement
• Speed ---------------------------- Velocity
• Mass ------------------------------- Weight
•Time -----------------------------------------------
• Energy --------------------------------------------
• ----------------------------------------------- Force
(magnitude & direction)

15. Some Units
Quantity .………………... Unit (symbol)
 Displacement & Distance ….… meter (m)
Time …………………………. second (s)
Velocity & Speed ……………….(m/s)
Mass ……………………… kilogram (kg)
 Force ………………………. Newton (N)

16. Some “SI Prefixes”
nano n 10-9
micro μ 10-6
milli m 10-3
centi c 10-2
deci d 10-1
deka da 101
hecto h 102
kilo k 103
mega M 106
giga G 109
Little Guys
Big Guys

17. 0.29 seconds
Another problem: A car travels 10,000 meters in 6
minutes, what is the car’s speed?
The answer

22. Graphing
A … Starts at home (origin) and goes forward
slowly
B … Not moving (position remains constant as
time progresses)
C … Turns around and goes in the other direction
quickly, going back home.
1 – D Motion
x
t
A
B

26. O A & D E
A B & E F
C D
B C

27. v = zero a = zero
d: increases v: constant
uniformly
a = zero
d: increases
nonu-niformly
v: increases
uniformly
a: constant
d: constant

28. Graphing Animation Link
Car Animation
This website will allow you to set the initial
velocity and acceleration of a car.
http://www.walter-fendt.de/ph14e/acceleration.htm

30. Thank you for being with
us. Have a nice day
Amal Sweis 