Page 107 - Viva ICSE Science 4 : E-book
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equal parts and have markings on them. To measure, we pour liquid in them and read
the marking till which the liquid touches.
In our daily life, we measure the volume of milk we buy, water and oil, and many such
things.
Measurement of Time
Time is the quantity that is measured using a clock or a watch. Seconds (s) is the standard
unit to measure time. Minutes (min) and hours (h) are the other commonly used units
in which time is measured.
In earlier days, people used to measure time by seeing the position of the sun in the sky.
But these days, diff erent types of clocks and watches are used to measure time.
A clock or watch has a dial. On the border of the dial, there are numbers
printed from 1 to 12 at equal distances. A clock or a watch has three
hands that move on the dial and help us read time. The three hands are
of diff erent lengths and remain fi xed at the centre of the dial. The hour
hand moves slower than the minute hand. The secondʼs hand moves the Wall clock
fastest among all. The hour hand completes one full round of the dial in 12 hours while
the minute hand completes a round in 1 hour. The secondʼs hand completes a round in
just one minute.
Did You Know!
Our daily life is guided by time. We get up at a particular
1 hour = 60 minutes
time, go to school and work at a fixed time, have our meals
1 minute = 60 seconds
at a particular time and so on. 1 hour = 3600 seconds
Measurement of Temperature
Temperature is the measure of how hot or cold an object is. Degree
Celsius (°C) and degree Fahrenheit (°F) are the two units that are used
to measure temperature. We usually use a thermometer to measure
the temperature.
A clinical thermometer is used to measure our body temperature. To
measure the body temperature, thermometer is cleaned with soap and
water or by rubbing alcohol on it before use. Then it is shaken firmly
until the mercury reads at or below the lowest number. The bulb of
Thermometer
the thermometer is placed under the tongue for one to two minutes.
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