A level physics OCR. Chapter 2: foundations of physics summary

SUNITS
2 1
.




OF BASEUNITS

TABLE There are seven different 'Base

quantities that all known equations are




=
derived from
. All correct equations can


be broken down into equal s 1 . units
.


(explained later (




LUMINOUS

INTENSITY




IGREFIXES
If you're given a calculation with S . l prefixes use


ENGINEERING FORM NOTStandard form
.


use an appropriate S I PREFIX
.




1S
XI0I5 PETA 2mm = 2x10- 3m




I
FEMTO g
_
e
-


x 10
=
= .




X 1012 =
TERA x10
-
12 = PICO
X109 =
GIGA X10 9
-
=
NANO

X 106 =
MEGA x 10
- 6 =
MICRO QUESTION
x103 =
Kilo x10
-
3 =
Mill
IF A CIRCLE HAS A RADIUS OF O 2 MM CALCULATE
.




x102 =
HECTO X10
- 2
= CENTI
THE AREA IN M2
X101 :
DEKA x10
- 1 = DEC
convert to m
3 3
THE
SIGNIFICANT FIGURE RULE 0 2 mm
-

. = 2 x 10
② write out equation + sub in values
when doing calculations , If you get a long answer A = πr2
you should always give your answer to the number A (T2x 10 3)2
-
=



of SIGNIFICANT FIGURES given in the question. A 7mz
13x10
-

=

-




question
Example
ICERTAINTY
CALCULATE THE AREA
uncertainty is defined as THE RANGE OF

OF THIS RECTANGIE .
VALUES WHERE A MEASUREMENT COULD LIE .




J
e THE UNCERTAINTY AREA
.

.
g OF THE OF

0 92m
. THE RECTANGLE COULD BE BETWEEN 2
&


&
VALUES .




4. 458M
2 SIGNIFICANT

FIGURES LARGEST AREA = 0 925X4 4585


Z
.
.




0 92x4 458
. . = ma SMALLEST AREA = 0 915X 4 457S
.
.