↑HY 1010
-
SECTION 3-LECTURES 1,2
↓
Chapter 1
Chapter 1
SID line)
Types of
motion:
**
- linear motion
2
-
-circular motion
general
1- ax+
-Rotational
bx+c-i),s
y
=
x"porabula
constant
motionis ridgid
ended objects)
Motion:
change of
Trajectory path
an
along
PARABOLA
object's
which the
2 IRCLE
2Dcircle
sporabula
-projectilemotion
in
a
position
object
in
accelerationon sg=9.87m/st)
time.
moves.
·f
~
i
Kinematics (branch of mechanics): study
how the
potion depends
on
time.
diagrams
a
constant
IOS IVSIOC
Example
1:
·878....
same
the motion how the
time
speed
suniform)
intervals
533s5s
Example 2:
or
·..
I
·
Example
3:
· Y
2x
o
Y
I
C
speeding
up
position
1
Example
4:
⑧
2,
F
min
⑧ 6
⑧
-
Example 5:
s
⑧4
so
clownas
isso
·
Kinematics,
For
speeding
up
down
-
we can make
an
(point particle approximation)
approximation
0 0.
*
~ diregard
V
Position:
the size, shape... of the
object
consider the position of the center of
only
first
o
pick
up
a
mass
refrence framescoordinated
ID
!!!!11cX()
My
object
at
is
x=3m:
meters: standard units of
length in SI system,
this
1
·
·
Position
is
Position
a
vector
the
is
1
so
(quantity
&
object.
N
vector
a
which has both
direction
magnitude
r
position of the
magnitude
X-axisJon[E]
Example: 3m
Lalong
x(m)
A
2D example of
At
what
use
the
is
position
magnitude r
-
of
3
+
10
=
9
+
1
=
Nr.
(3,1)
-
x
(m)
-
pythagorean theorem to find lengh
r=
r0
=
N0
r..
and direction)
what about
the direction
*
of ri? find
angle
o
unites the
tant-opp:<M=E<dimensionless,
r
18.40.
Artan)" s)
Vector
=
Nom (E18.4.NT
=
↑imet(s)
<seconds)
we are
*
mostly intrested
z
tz-t,
=
E
xample: particle
T
Scalar
hen,
:tr-ti
Dt
oR
at
is
At
time intervals.
in
=
At
delta
point
tx-t.=
A
(change
att.=5:00pm, and
1:30
on
th and
a
then at point Bat tc
=
6:30pm
half
Vector
us
-
speed
↑
tempurateone
Scalar: only magnitude e.g Varg, T,
Vector:
a
magnitude
vector that shows the
ar
-
direction
change
M, t,
density
(*)
egposition (r), Varg, d. weight, force
& is placement (AF)
in
the
velocity
position
re- r Fr-Fi
=
=
Example:
ri
Position vectors:
A
position
at the
vector
starting
-A
-
-rL
Ar
T
at the
origin,
end at the location
-
point
F position
start from the
r
of
the
r
object
vector
endpoint
brokeofthis
is
r=
the displacement
-
&
S
a
r0
&
is
reactin
rz -r
Dr =
=
Dr =
-
final position
what
3
Motion
through displacement
"BE.
Examples of displacement
*
-
Arz
Diagram
Ar,
because
Example: CID motion)
what
DFz
I
endto
is
Av
total net displacement?
Sinet:
28
10
DF,
is
not
Arz
+
+
+Ars
Arnet=rr r
=
ri
displacement?
yFz Arx
+
0
=
Hence, Arnet =0
N
>
Ar3
Bri
&
However,
the
distance
trajectory/path
In
this
case,
&
velocity
not
zero. It is in
fact the
of motion,
distance (d)=Ar.
inits
Notation:
is
of
length
magnitude
+
Are, Arg, Ary
length
Ar,
or
+
Ar
+
=
goal: to find the
final position initial postion
Ar
+
rp r
on
Our
r
length
of
-
A r2
of vector
"cavector quantity)
F: AonlEl
length of
the
displacement