2022 | Resumo da Aula | 1ª Série | Matemática | Aula 3 - Sistema Internacional de Unidades (SI) III

Summary

In this educational video, teacher Eliane introduces the International System of Units (SI) and discusses some common units that, while not part of the SI, are still frequently used in scientific, technical, and commercial contexts. She explains various units of length, mass, and volume, including the nautical mile, ton, and liter. The video also covers practical examples, such as measuring food items like rice and sugar in kilograms and liters, and how different countries may use multiple units, like pounds and grams, to measure products. The video aims to provide a clear understanding of these units and their real-world applications.

Takeaways

• 😀 The International System of Units (SI) is a global system for defining and using standard units of measurement.
• 😀 While SI units are internationally recognized, some non-SI units are still used in scientific, technical, and commercial contexts.
• 😀 Examples of non-SI units for length include the nautical mile (1 NM = 1,852 meters), the terrestrial mile (1 mile = 1,609 meters), and the light year (1 light year ≈ 9.6 x 10^12 kilometers).
• 😀 For mass, non-SI units like the ton (1 ton = 1,000 kg) and ounce (1 oz = 28 grams) are still commonly used.
• 😀 The liter (L) is a non-SI unit for volume, equivalent to 1,000 cubic centimeters (cm³), but it remains widely used.
• 😀 In Brazil, the cost of the national basic food basket is an important economic indicator, which includes items like rice, beans, cocoa powder, sugar, oil, and milk.
• 😀 For solid foods like rice and beans, weight is measured in kilograms (kg), whereas liquids like oil and milk are measured in liters (L).
• 😀 Products sold internationally may list quantities using different units, like grams and pounds, depending on the country.
• 😀 1 pound (lb) is equal to 450 grams, and the script demonstrates how to convert pounds to grams using a simple proportional calculation.
• 😀 The video concludes by summarizing the importance of understanding and using SI units for standardized measurement in various fields.

Q & A

What is the International System of Units (SI)?

The International System of Units (SI) is a system that provides internationally recognized reference units, on the basis of which all other units are defined.

Are there any units that are still used outside the SI system?

Yes, some units are still used in scientific, technical, and commercial publications, even though they are not part of the SI system. These units will continue to be used for many years.

What are some examples of length units that are not part of the SI system?

Some examples of length units outside the SI system include the nautical mile (152 meters), the terrestrial mile (1609 meters), and the light-year (9.6 x 10^12 kilometers).

Why is the light-year represented using scientific notation?

The light-year is represented in scientific notation because it represents a very large distance. Writing it as 9.6 x 10^15 meters simplifies the expression of such a large number.

What are some mass units that are not part of the SI system but are still used?

Some mass units outside the SI system include the ton (T), which equals 1000 kilograms, and the ounce (oz), which equals 28 grams.

How is volume measured in the SI system and outside it?

In the SI system, volume is measured in cubic meters (m³), but the liter (L), which equals 1000 cubic centimeters (cm³), is commonly used outside the SI system.

What is the 'basic food basket' in the Brazilian economy, and how is it measured?

The basic food basket in Brazil is a set of 13 food products, including rice, beans, chocolate powder, sugar, oil, and milk. Solid foods like rice and beans are measured in kilograms (kg), while liquids like oil and milk are measured in liters (L).

What does the packaging of a product typically show regarding units of measure?

Products often show quantities in multiple units of measurement, depending on the country of sale. For example, a treatment cream may show its weight in grams (g) and pounds (lbs), with 1 lb equaling 450 grams.

How do you convert pounds to grams for product measurement?

To convert pounds to grams, you can use the conversion factor that 1 pound equals 450 grams. For example, 2.23 pounds would be approximately 1000 grams (1 kilogram).

What was the final example in the video about measuring product weight?

The final example showed a product weighing 2.23 pounds. Using the conversion factor of 1 lb = 450 grams, the result was approximately 1000 grams, or 1 kilogram.