Physics: Measurement, SI Units, and Proportions

What must a measurement include?

Both a number and a unit (e.g., 15 inches, 15 miles)

What does SI stand for?

International System of Units

How can metric prefixes be used?

To adjust the values of base units by factors of 10

What is the metric prefix for 1000?

Kilo (1 km = 1000 m)

What is the metric prefix for 0.01?

Centi (1 cm = 0.01 m)

What is the metric prefix for 0.001?

Milli (1 mm = 0.001 m)

What are derived SI units?

Combinations of units resulting from mathematical operations

Give an example of a derived unit for volume.

cm³ (1 cm³ = 1 mL = 1 cc)

What is the formula for density?

Density = Mass / Volume

What is dimensional analysis?

A process used to convert between different units

How do you convert using dimensional analysis?

By creating conversion factors from equivalent statements and canceling out units

What does accuracy refer to in measurements?

How close a measurement comes to the actual value

What does precision refer to in measurements?

How close a series of repeated measurements come to each other

What are significant figures?

The digits in a measurement that reflect how well the quantity is known

What is the Atlantic rule for counting significant figures?

If a decimal point is absent, start counting from the Atlantic side of the number

What is the Pacific rule for counting significant figures?

If a decimal point is present, start counting from the Pacific side of the number

How should you round answers when adding or subtracting significant figures?

To the same number of decimal places as the measurement with the fewest decimal places

How should you round answers when multiplying or dividing significant figures?

To the same number of significant figures as the measurement with the fewest significant figures

What is a direct proportion?

When the ratio between two quantities remains constant

What is an inverse proportion?

When the product of two quantities remains constant (xy = constant value)