Unit 1 - General Physics

AS LEVEL
PHYSICS

,1 Physical quantities and units ................................3

1.1 Physical quantities ........................................................3
Estimation ...................................................................4
1.2 SI units ........................................................................4

1.4 Scalars and vectors .....................................................7

2 Measurement techniques ................................... 10

2.1 Measurements ...........................................................10
2.2 Errors and uncertainties .............................................11

Errors ........................................................................12
Precision and accuracy...............................................12
Treatment of uncertainties ...........................................13

, 1 PHYSIC AL
QUANTITIES AND
UNITS
The measurement and recording of quantities is central to the whole of phy
estimating a physical quantity and having a feeling for which quantities are
and which are unreasonable are very useful for any physicist.


This topic introduces the SI system of units, which provides a universal fram
measurement that is common to all scientists internationally.


Candidates should be aware of the nature of a physical measurement, in te
magnitude and a unit. They should have experience of making and recordi
measurements in the laboratory.



1.1 P H YS I C A L Q U A N T I
LEARNING OUTCOMES

C ANDIDATES SHOULD BE ABLE TO:

A. understand that all physical quantities consist of a numerical magnitude

- Physical quantities have a numerical value and a unit; in physics, it is esse
units of physical quantities. For example, mass can be measured in kilogra

might write mass of trolley as: