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mathematicsprinted 18 · PDF 19
165 pagesrevision 46935
printed 18 · PDF 19
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Speed – how much the distance changes for each unit of time
Density – how heavy something is for each unit of its area or volume
Pressure – how much force is applied to an object for each unit of its area
Flow rate – how much the volume changes for each unit of time
Population density – how many people there are for each unit of area
Formulas: *Required formulas according to the question will be given.
Speed = Distance / Time
Density = Mass / Volume
Pressure = Force / Area
Understanding Time Units
(Time is one of the simplest concepts in the igcse mathematics syllabus which
can give you a lot of problems if you have a weak foundation of the basic
concept.)
We know that an hour hand takes 12 hours to go round the clock. It goes round the
clock twice in a day so, 1 day = 24 hours. The minute hand takes 60 minutes to
complete one round on the clock. So, 1 hour = 60 minutes.
Again, we know that there are 12 months in a year. The months of January, March,
May, July, August, October and December have 31 days. The months of April, June,
September and November have 30 days. The month of February has 28 or 29 days.
In a week there are 7 days. 1 day is equal to 24 hours.
The standard units of time are:
1 hour = 60 minutes
1 minute = 60 seconds
1 hour = 60 minutes = 3600 seconds (60 × 60)
1 day = 24 hours
1 week = 7 days
1 year = 365 days
This simple but concise graph covers all the conversions you will need to
know to attempt any questions about time.
Difference between 12 and 24 hour clock