Page 7 - MEASURING MASS, LENGTH AND TIME

The scale will automatically show the result. Next, read the result and

enter your answer on the column
5. Choose the suitable result.

6. Do the same procedure for the other object. Then, write how may correct
numbers do you get.

C. MEASURING TIME
We know that the measurement of time is read by a clock or a watch. Any

clock or watch except a digital watch, has a dial. On the circular border of the

dial of a watch or clock there are the hour numbers from 1 to 12 at equal
intervals. Between the two numbers there are five divisions. Each division

represents a minute.
The standard for unit of time, the second (s), is the exact duration of

9,192,631,770 cycles of the radiation associated with the transition between the
two hyperfine levels of the ground state of cesium-133 atom.

The following are the example of time measuring devices

Atomic clock Used to measure very short time intervals about
0,0000000001 second

Digital stopwatch Used to measure short time intervals of minutes and
seconds to an accuracy of 0.01 second

Analogue stopwatch Used to measure short time intervals of minutes and

seconds to an accuracy of 0.1 seconds