Welcome to this experimental science test. We hope that you will find it interesting and worthwhile. Carefully read through these directions and the directions on the next page before you begin to work.

You may be part of a group for the first part of this exercise. Each group should carry out the experiment and collect the data together, but each student must record the data in his or her own booklet. Be sure to record the data exactly as you observe them. After the data have been collected, each student should answer the questions independently.

After you have finished your experiment and have recorded all of the data, you will be asked to answer some questions about the experiment and the data you recorded. Your answers must be written in this test booklet in the space provided. Make sure that you understand each question before you begin to write. At any time while you are writing your answers, you may look back at the directions for the experiment and the data you collected. Be sure that your answers are written as clearly and neatly as possible.

Before you turn the page, read the list of materials given below and check to make sure that your group has everything listed.

Submersible vessels, such as submarines, have long been used in underwater exploration and treasure hunting. The vessels must be capable of descending and ascending to different levels in the water. This is accomplished by increasing or decreasing the vessel's mass, and therefore, its density. In this investigation you will have the opportunity to study how an object's density affects its ability to float in water. You will work in groups to gather data. You will answer the questions on your own.

You are going to make boats from aluminum foil to see how many washers they can support before sinking. You should follow the directions below and record the data in the data table below.

1. Use a piece of aluminum foil 15 cm long x 15 cm wide to create a boat that will float in the aquarium.

2. Measure the length and width of the bottom of the boat. Measure the height of the boat. Record this information in Table 1 below.

3. Find the mass of the boat.

4. Add washers to the boat, one at a time, until the boat sinks. In Table 1 record the mass of washers added to the boat to make it sink.

5. Repeat this process, making boats of different shapes and determining how many washers they will hold before sinking.

Table 1

Boat	Length (cm)	Width (cm)	Height (cm)	Mass of boat without washers (g)	Mass of washers added to boat (g)
1
2
3

Please answer the following questions by yourself.

1. Calculate the density for one of the boats you made, including the mass of the washers that made the boat sink. Show your work. Compare the density you calculated for the boat and washers to the density of water. (The density of water is 1 gram/ml). When the boat sank, should the density of the boat and washers have been higher or lower than the density of water? Explain your answer.

2. Suppose that your lab partner creates two boats from two identical pieces of aluminum foil. The volume of Boat 1 is 500 cm³. The volume of Boat 2 is 400 cm³. Which of these boats will be able to support more mass before sinking? Explain your answer.