Estimating & Measurement of Fundamental Quantities
Estimating & Measuring Length
Definition of length:
Length has a magnitude and an S.I unit. The S.I unit of length is a
metre (m). But there are other units of length like, millimetre(mm),
centimetre(cm), and kilometre(km) that are commonly used.
Qn: Mention other units of measuring length.
Conversion of units of Length
Key Question: How can you convert from one unit of length to another?
What to do:
a) Find out the relationship between millimetre, centimetre, metre,
and kilometere.
b) Convert the following measurements
(i)
5 km to m
(ii)
200cm to km
(iii) 1000mm to cm
c) Develop your own conversion table
Possible Responses
Example
The width of a building is found to be 10.4 m. What is the length
in millimetre?
Exercise 2.1 (baroque Page 16)
Instruments for Measuring Length
Before carrying out measurement, you should have an idea about
the quantity to be measured. Is the quantity large, small, very
small or micro? In otherwords, you should have an estimate value
of the quantity. This enables you to select the units of
measurement and also choose an appropriate instrument to use.