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# Scientific Measurement

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Practice Scientific Measurement
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Devil is in the details

### Devil is in the details

Credit: Batholith
Source: http://en.wikipedia.org/wiki/File:Kitchen_scale_20101110.jpg

What is the importance of having a precise standard for the kilogram?

#### Why it matters

• In response to the question above, this is due to the fact that the kilogram helps define many of the SI units in the SI system. From a Newton (the measure of force) to amperes (the measure of current), a precise standard must be used otherwise any uncertainty in measurement and in application would be unknown.
• Currently, the kilogram is the only SI unit that is still defined by an actual physical object. Recent propositions are being considered to redefine the kilogram in terms of the Planch constant, $h$.
• You can read more about the importance of the SI system and the kilogram unit of measurement with the links below:

#### Can You Apply It?

Using the information provided above, answer the following questions.

1. The stability of the kilogram is extremely important because the kilogram defines many units of measurement in the SI system. Since a force is defined in terms of Newtons, where a newton is 1 kilogram•meter / sec2, how would the weight of an object be dependent upon knowing the precise value of a kilogram?
2. What are the seven base units that are considered the building blocks of the SI system?