Comprehensive General Physics 1 Class Notes

We use INSTRUMENTAL !

Chapter 1: Units ,
Trig 3 , vectors !
↓ 5128/24
>
Significant Figures : assuming it comes from an


2x103 I sig fig :




.
instrument (instrumental approach)
figs
3
2 QQQ :
4
Sig .
Think that there is an instrument that could
measure that accurately ! (powers of 10
02004 :
. 4
sig .


figs * More for X do not count )
!
LAB !
2x104 : I sig fig .

* Theoretical approach : 2000 >
-
1
sig fig
For should have least amount
sig figs
multiplication of !
·
:
solution .




M = 3 1415
.
< T ·
2 -
103 =
6x103 ONE SIG FIG


Multiplying by constant does not change the number of
sig figs in
·


a


the result !

> Vectors :

3
>
"3
-




Y
O
A : : units in X direction"
3- ·
B :
2Y :
"a units in
y
direction"

2x * / unit vectors :


1
· 2x3 "2 units in
-




:
direction + Sunits
i2X
:
x

in y direction"
~
You can NEVER mix the * w/ Y !


:
Ex
1
* Book notation :

m + B = 3X +
y Y = T Y =
J
·

Analytical Addition/Subtraction of Vectors :

Ex : = -
SY -



6Y
a
- x 2)
=
-
7X -




2Y
i a - =
2 -


4y :
( -
Sy -

Gπ) -




Ex ::
2x +
34 a -
5 + E - : -


64 + 154
-
1
X 2y
-




2x +
14
: 5x
1

3y
-




a + 5 + 2+ :
6Y +
SY

, ·

Graphical Method of Addition / Subtraction of Vectors :




*
* T
A v (STEP1))

A
7
·

SOLUTION !




1) More one vector to the tip of the other vector !

* Can NOT
change the size or inclination of the vector!
-
> Count squares to ensure ACCURACY !!

2) Join Origin (0 0) , with tip of translated vector !

* You can use analytical method to check:
>

Analytically !
-




: 3Y
3
Creck

SAME RESULT ! a 3x Y
= -




a +5 :
5y 5 =
2x +
34
1
* FOR SUBTRACTION :
5 1 5 - =
Y -


4y
>
-




a


1
S

a - 5 =
? Solution !

~
·

X 1) You just join the tip of
one vector w/ tip of other

Vector .




2) Tip of arrow faces from
-

b to a

, Subtraction
~
w/3 Vectors :




M 1 a -
5 -

5 =
?

↓ Solution
·
6x 74
↓
-




1) Subtract first 2 vectors like

normal .


# 2) More that solution to the


origin properly.

3) Repeat subtraction steps by
(Completes HW 1 Material) 2 tips.
joining
~
Vectors :
-
a = 3x + 24


2 -Magnitude : 1)
la)
=




=
3 + 22 Pythagorean
13
Theoryis



i' 27 11 =
3 6
.




-




Magn .
Formula:
|| =
a2x + a
?

11
15) = 22 + 22 -




=
8 = 2 8 .




] * Can't
get a
neg .



magnitude bic of
squaring !!
-

Orientation Direction : The
angle with respect to the horizontal !
!



tan) Sinopposite *Cos
SOHCAHTOA
hypotenuse
*
T

magnitude Oy : Adjacent tan : Opposita
O Copposite)
an (5)
↓ =+
ax
Hyp Adjacent
ladjacent)
0 =
33 . 70

, ~
In Physics most of the time you have the O and the Hypotenuse !



hypotenuse ay
SinO =
Opposite
hypotenuse
=
Ay
hyp
O F Ay =
Hyp xSin8
aX
Ay = 3 . 605xSin (33 . 6)
Ay =
1 995
.
!!
* Normally you will be asked to solve for Ax or My !

COSO
as
Solve for ax ? =A
= hyp
Cos (33 . 6) ·
3 605 .
= Ax
Ax =
3 00 .




Chapter 2 : Motion in One Dimension : Only happens in or Y or
-


Object is
moving only in Y or only in Y !
~
Displacement : total distance advanced * =
* -
2 x
a =
C =. 5x :
Displacement ZERO ! =




+ 3 S -


=
0 0 =
Displacement
=




a =
y 5 3x5
= =
2x
a + 5 + E x 3 = + +
2x = GX =
Displacement
* Displacement is a VECTOR !!
Distance of displacement
~


Magnitude
:




Distance 1212 *Typical unit meters (m)
62
=
is
X +
y
= =
6
[meters] =
[m] SI (MKS(
~
Velocity : - :
Vector velocity >
"Average Speed" VECTOR
15) :
speed >
"Average speed" Not Vector

Also, Instantaneous Velocity Instantaneous Speed At
specific
·
+
-




point !
distance
1%1 : Speed :
&X =




time
= 6m = 3 M/S : "meters per second"

Or "V" 2S