Page 64 - Innovator's Science-8

When an object is hung from a spring, the spring stretches due to the
force applied on the object by the Earth. We find that the stretch caused

in the spring is different for different objects. This indicates that the
(a)
Earth pulls different objects with different forces, that is, the weight of
different objects is different. Can we use the spring to measure the
weight of an object?

Let us now try to find the smallest value of weight that can be measured
by the spring balance.

Look at the spring balance shown alongside and note down the
(b)
following:
(a) A hanging spring;
(b) Two different objects hung • How much is the weight difference indicated between the two bigger
from the spring
marks? The weight difference indicated between 0 and 01 N or
between 01 N and 02 N is 1 Ν.

• How many divisions (shown by smaller marks) are there between
these two bigger marks?

There are 5 divisions between these marks.

• How much weight does one small division indicate?
One small division can read 1 N 5 = 0.2 N.

A spring balance and Object suspended
close-up of its scale from a spring balance
So, the smallest value that the spring balance can read is 0.2 N. Now
using this method, calculate the smallest value of weight that can be
measured with the spring balance given to you. Your school laboratory

may have spring balances for which the range and the value of the
smallest division may be different. It is, therefore, always necessary to
look carefully at the spring balance (or any other instrument) you are
about to use.

The mass of an object can be found by measuring its weight. This can be

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Science-8