الموازين ( آلات الوزن ) - الميزان الزنبركي .. الآلات التي نستخدمها كل يوم

Scales (Weighing Machines) - Spring Balance
.. The machines we use every day and how they work

Scales (Weighing Machines):

Laundry scales, kitchen scales, bathroom scales, and postal scales all work in the same way despite the apparent difference in their shapes and sizes. Let us study the way in which these scales work. What happens if you tie a wooden block to one end of a rubber band

and then pull the other end? The rubber band will stretch a little, say by an inch. If you tie a second block equal to the first block to the end of the same band, the rubber band will stretch twice as much as it did the first time, say by two inches. In the same way, the rubber band will stretch three inches if you tie three blocks to it. And so on (until the rubber band breaks).

Now let us remove these wooden blocks and attach a hammer (sledgehammer) instead of them. If the rubber band stretches two inches, we will realize that the hammer weighs two blocks. If it stretches three inches, this means that the weight of the hammer is equal to three blocks, and so on.

Spring Balance:

The same stretching also occurs in this small balance called the spring balance. In it, a metal spring replaces the rubber band, because the rubber loses its tensile strength if it gets old and is used a lot.

The degree of spring tension is measured by an indicator that moves in front of a graduated ruler. When you hang a light object on the spring balance, the spring stretches a little and the indicator moves to a small number, while a heavy object causes a greater stretch in the spring, and therefore the indicator moves to a number larger than the first number.