Kinematics : a branch of physics that studies motion

Describing Motion

Photo taken by Rasha Alkhateeb Jubilee School

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

Mass vs. Weight

your mass would be the same, but the magnitude of your weight would be less.

Mass• Scalar (no direction)• Measures the amount of matter in an objectWeight• Vector (points toward center of Earth)• Force of gravity on an object& On the

moon!!!

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

Some UnitsQuantity .………………... Unit (symbol)

Displacement & Distance ….… meter (m)

Time …………………………. second (s)

Velocity & Speed ……………….(m/s)

Mass ……………………… kilogram (kg)

Force ………………………. Newton (N)

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

Another problem: A car travels 10,000 meters in 6 minutes, what is the car’s speed?

0.29 seconds

The answer

1) a 2) b 3) a

3.3 m/s

“Distance versus Time” Graphs

Graphing

A … Starts at home (origin) and goes forward slowlyB … 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

AB

C

SPEED IS THE SLOPE OF THE DISTANCE VERSUS TIME

GRAPH

DISTANCE VS. TIME GRAPHS

O A & D E

A B & E F C D

B C

a = zerov = zero

v: constantd: increases uniformly

a = zero

d: increases nonu-niformly

v: increases uniformly

a: constant

d: constant

Graphing Animation Link

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

Car Animation

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