Densities of a Few SubstancesConceptual Physics

Text Correlation: Section 18.2

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Question 1

• Which is heavier, balsa wood or pine?

• Answer: There is not enough information in this question for an answer. Certainly a ton of balsa wood is heavier than a few kilograms of pine. If it is meant which is heavier, balsa wood or an equal volume of pine, then the pine is heavier. Distinguish between weight (or mass) and volume.

Question 2

• Which metals in the table will sink in mercury?

• Answer: Metals from osmium through uranium, except lead, will sink in mercury. Lead is less dense than mercury, so will float in mercury. We'll learn in Chapter 19 that objects denser than water will sink in water. Likewise for other materials.

Question 2

• Which is denser, a gram of gold or a ton of gold?

• Answer: Both have the same density!