What is mass, and how does it differ from weight?

List three examples each of objects that are commonly measured by mass, by volume , and by length.

Applying Concepts You throw three darts at a dartboard. The darts all hit the board near the same spot close to the edge but far away from the bull'seye. Were your throws accurate or precise? Explain.

Significant Figures Write the answers to the following calculations. Be sure to use the correct number of significant figures. a. $15.75 \mathrm { m } \times 8.45 \mathrm { m }$ b. $5,650 \mathrm { L } \div 27 \mathrm { min }$

Explain why the observation that the sun sets in the west could be called a scientific law.

Explain in your own words why scientists use significant figures.