PETUNJUK PRAKTIKUM PENGUKURAN MASSA MENGGUNAKAN NERACA 4 LENGAN (OHAUS) KELAS 7

Summary

In this educational video, the instructor demonstrates how to use a four-arm balance scale to measure the mass of various objects made from different materials. The five objects being measured include iron, wood, copper, aluminum, and brass. The video explains the function of each arm of the balance scale and guides students step-by-step through the process of achieving a balanced scale and accurately reading the mass. The instructor emphasizes the importance of ensuring the scale is calibrated correctly, offering a practical and hands-on learning experience for students.

Takeaways

• 😀 The lesson involves using a four-arm balance scale to measure the mass of different materials.
• 😀 The four-arm balance scale has four arms with different divisions: hundreds, tens, ones, and decimal fractions.
• 😀 The scale's metal tray is where the object being measured is placed for balancing.
• 😀 Always ensure the pointer is at zero before starting the measurement process.
• 😀 Start balancing the scale by adjusting the largest weight division (hundreds), and move to smaller divisions if needed.
• 😀 If the scale isn't balanced, adjust the weights incrementally and check the needle position.
• 😀 To achieve precise measurements, use the decimal or fractional weight arm for fine-tuning.
• 😀 After balancing, read the mass by adding up the values shown on the hundreds, tens, ones, and decimal divisions.
• 😀 An example mass reading is 64.3 grams, derived from a combination of values from different arms.
• 😀 Practicing with different materials (iron, wood, copper, aluminum, and brass) will help students get familiar with using the scale.
• 😀 The importance of carefully adjusting the weights to ensure the scale is perfectly balanced and the needle is at zero is emphasized.

Q & A

What is the purpose of using a four-arm balance in the experiment?

The purpose of using a four-arm balance is to measure the mass of various objects with high accuracy. The balance helps ensure precise measurement by comparing the mass of the objects with calibrated weights.

How many objects are to be measured in the experiment, and what materials are they made from?

There are five objects to be measured, made from different materials: iron, wood, copper, aluminum, and brass.

What is the maximum capacity of the four-arm balance used in the experiment?

The maximum capacity of the four-arm balance used in the experiment is 311 grams.

What is the purpose of the metal tray on the four-arm balance?

The metal tray is used to place the objects whose mass is being measured. It is positioned on the four-arm balance to facilitate accurate measurement.

What should be ensured about the needle indicator before using the balance?

Before using the balance, the needle indicator must be aligned with the zero mark on the scale to ensure accurate measurement.

What do the different arms on the balance indicate?

The four arms on the balance represent different measurement scales: hundreds, tens, ones, and decimal fractions. Each arm helps refine the measurement to a precise value.

How do the holes on the arms of the balance help in measurement?

The holes on the arms of the balance correspond to specific values that are used to indicate the mass of the object being measured. The holes must align correctly with the scale to provide an accurate reading.

How is the balance adjusted if it is unbalanced during the measurement?

If the balance is unbalanced, adjustments are made by shifting the weights along the arms until the needle indicator points to zero, signaling that the balance is now in equilibrium.

In the example of measuring the mass of an iron object, what was the final measured mass?

The final measured mass of the iron object was 64.3 grams.

What is the importance of starting the measurement from zero on the balance?

Starting from zero is crucial because it ensures that the balance is calibrated correctly, and the measurement reflects the true mass of the object, without any prior bias or error.