Science and Technology^155
FIND OUT MORE. Physics 163
Mathematics explores the
properties (characteristics) of
numbers, shapes, and space.
Using maths, scientists can
describe patterns they observe in
nature, and make models that
explain how things behave.
4 DODECAHEDRON
Geometry is the branch of maths
that studies shapes. Engineers
use shapes like this to help
them create new designs.
This shape has 12
identical faces. Each face
is a regular pentagon
(five-sided flat shape).How big is an ant? How high is a mountain? An observation of a property
(characteristic) as a number on a scale of units is a measurement. A child’s
height may be measured on a metre scale as 1.2 m (4 ft).
HOW ARE MEASUREMENT UNITS FIXED?
Units are fixed by international agreement. Scientists
define a standard against which scales can be
calibrated (set and checked). The standard kilogram
is the mass of a platinum-iridium cylinder kept at
Sèvres in France. The metre is defined as the distance
travelled by light in 1/299,792,458 of a second.WHAT ARE MATHEMATICAL MODELS?
Mathematical models are equations that describe real
processes. For example, a simple model based on the
laws of motion predicts that the speed of a falling
stone is equal to the time it has been falling,
multiplied by the acceleration due to gravity. The
predictions of the model can be compared with real
measurements to test the model’s accuracy.
WHAT IS SCIENTIFIC NOTATION?
Scientists measure anything, from very large numbers,
such as the speed of light, to very small numbers,
such as the mass of an atom. Scientific notation is a
shorthand way of writing these numbers. The speed of
light is approximately 300,000,000 metres per second.
This is shortened to 3.0x10^8 m/s, where^8 is the
number of zeros that follow the 3.WHO MADE THE FIRST MEASUREMENTS?
Early people used measurements to build structures
such as Stonehenge and the pyramids. Many
measurements from this time were based on parts of
the body – a cubit was the distance from the elbow
to the tip of the fingers on an outstretched hand.WHAT IS A MEASUREMENT SCALE?
A simple measurement scale is a series of numbered
graduations (marks) on a measuring instrument.
Modern electronic instruments often have digital
readouts that automatically display the reading.
Measurements
1 MEASURING INSTRUMENTS
Different measuring tools are used to measure different
things. Balances measure weight, stop watches measure
time, measuring cylinders measure volume of liquids, and
thermometers measure temperature.Mathematics
QUANTITY UNIT NAME SYMBOL
Base units
Mass kilogram kg
Length metre m
Time second s
Electric current ampere (amp) A
Temperature kelvin K
Derived units
Area square metre m^2
Volume cubic metre m^3
Density kilogram per cubic metre kg/m^3
Speed metre per second m/s
Acceleration metre per second squared m/s^2
Force newton N (kg m/s^2 )MEASUREMENT UNITSFIND OUT MORE. Electronics 188
BALANCE STOP WATCH MEASURING CYLINDERS THERMOMETERmeasurementsmathematics