Step 1:

Your instructor has modified Step 1.Instead of using lead, wood, Styrofoam, and a double beam balance, your instructor is providing information about cubic blocks that we have at our Pecan Campus.The blocks are shown in the following picture.

The following table provides the information that you need about the blocks.Notice that all the blocks have exactly the same volume.

Material	Mass (grams)	Volume (inches3)
Wood	9.8	1
Aluminum	45.1	1
Steel	128.9	1

Your task for Step 1 is to compare the volumes and densities of the blocks.

Step 2:

The comparison of densities is supposed to be a qualitative comparison, without using any numbers.Hint: For this lab, you can assume that if an object sinks it must be denser than water.

Step 3:

The volume of water displaced is equal to the difference between the initial and final volumes of water in the measuring cup.

Step 4:

To dissolve salt in the water, it is helpful to remove the egg so that you can stir in spoonful's of salt without the egg being in the way.

Procedure

Step I: Balance equal masses of lead and wood, using a double-beam balance. Repeat, using an equal mass of Styrofoam. 1. How do the volumes compare? How do the densities therefore compare?

Step 2: Try floating cans of soda pop.

2. Which ones float? Sink?

3. How does the density of the different kinds of soda pop compare to the density of tap water?

4. Hypothesize how the relative densities relate to sugar content.

Step 3: Use a balance to measure the mass of an egg.

Using a wide-mouth graduated cylinder, carefully determine the volume of the egg by measuring the volume of water it displaces when it is slowly (gently!) lowered into the graduated cylinder. Calculate its density: d mN. Density= _______________

Step 4: Now try to float the egg in a bowl of water. Does it float? If not, dissolve enough salt ln the water until the egg floats.

5. How does the density of an egg compare to that of tap water?

6. To salt water?

Summing Up

1. Does adding salt to the water make the water less dense or more dense? How?

2. Why do some people find it difficult to float while others don't? What evidence can you cite for the notion that it is easier to float in salt water?