Time

The ideal of time and timing!🤔

Concepts of time
Ways of measuring time i.e. old methods and modern methods

At the end of this lesson, the students should be able to:

• explain the concept of time;
• list at least 5 ways of measuring time both old and modern methods;
• calculate and solve simple conversion of sub-multiples of the fundamental unit of time i.e. second

WEEK 3
Topic: Time
Sub – Topics:
·         Concepts of time
·         Ways of measuring time i.e. old methods and modern methods
 
CONCEPT OF TIME
Time is the interval between events. It is a fundamental quantity with a fundamental unit of second.
 
MEASUREMENTS OF TIME
Time is measured using the following instruments as illustrated in the table below for the measurement of fundamental and derived quantities.
 
MEASUREMENT OF FUNDAMENTAL QUANTITIES

Quantity	Measuring instrument
Length	Rule e.g. meter rule, tape rule etc.	·        For measuring large distance between two points e.g. length of a field, length of an exercise books or clothes etc. ·        Most rules have a measuring accuracy of 0.1cm
	Vernier callipers	·        For measuring the internal and the external diameter of test tubes, rods, or pipes. ·        It is more accurate than the rules. ·        Its measuring accuracy is 0.01cm (0.1mm)
	Micrometre screw gauge	·        For measuring very small distances such as the thickness of a sheet of paper, the thickness of a plate of metal etc. ·        It is more accurate than the vernier callipers. ·        The measuring accuracy of the micrometer screw gauge is 0.001cm (0.01mm)
Mass	Chemical balance Lever balance Beam balance
Electric current	Ammeter
Time	Stopwatch/clock Ticker tape timer  Quartz clock Heartbeat Hourglass Atomic clock/watch
Temperature	Thermometers

 
MEASUREMENT OF SOME DERIVED QUANTITIES

QUANTITY	MEASURING INSTRUMENT
Weight	Spring balance
Volume	Volumetric flask, measuring cylinders, burette, pipette etc.
Electric power	Wattmeter
Speed/velocity	Speedometer
Electromotive force (e.m.f)/voltage	Voltmeter

 
Form the above table, it is clear that time measurement can be categorized into old means and modern means of measurement of time.
 
CLASSWORK
State another sub multiples for time measurement
Class Activity (Experiment)
The measure of time of events
 
ASSIGNMENT
1.   Explain how the heart can be used to measure time interval
2.   What is a second?
 
CONVERSION OF TIME

60 seconds = 1 minute

60 minutes = 1 hour

24 hours = 1 day

365 days = 1 year

∴365 ×1day=1year

365 ×24hours=1 year

365×24×1hour=1year

365×24×60minutes=1 year

365×24×60 ×1 minute = 1 year

365×24×60×60seconds=1 year

∴31,536,000 seconds=1 year

366×24×60×60seconds=1 leap year

∴31,622,400 seconds=1 leap year

360°=24hours

∴1°=(24×3600seconds)/360

1°=240 seconds 

so that,1°=4 minutes

CLASSWORK
Find the equivalence of the following in seconds
1.   The days of the month of October 2010
2.   Convert 31days to second
3.   What is the value of 1year (365 days) in seconds?

ASSIGNMENT
Find the number of seconds you have spent on earth so far.
Hint: state your birth date/day then proceed
 
CLASS ACTIVITIES – Experiment  
1.   Use of meter rule, Vernier callipers, micrometre screw gauge
2.   Identification of the instrument for measuring the fundamental quantities