For this project, you will need: heavy-duty aluminum foil, a metric ruler, tap water, a large, clear bowl, scissors, a hammer, graph paper and a permanent marker. Fill the bowl two-thirds full with water. Measure and cut out three 25-centimeter squares of aluminum foil. Use the permanent marker to mark the corners of each foil square for easy recognition. Draw the corners of one square together and crumple it into a ball about 6 centimeters in diameter. Measure and record the exact diameter of the ball. Gingerly place the ball atop the water in the bowl. Record whether the ball sinks, partially sinks or floats. If it partially sinks, estimate the percentage of the ball that is below the water. Remove the foil from the water and dry it with a towel. Crumple the square into a smaller ball of 5 centimeters in diameter. Repeat the process you applied to the larger ball. Continue making the ball smaller and recording the observations until the ball sinks. Repeat the entire procedure with the other two aluminum squares, using the same diameters as for the first square. At what diameter did the aluminum foil sink? Explain the reason for the smaller ball sinking.
You will need an aquarium, water, a stopwatch, a drill and about 1,800 grams of shotgun shot. Purchase or make 16 wooden blocks, four of each shape: spheres, cones, cubes and cylinders. Hollow out the center of each block with a drill. Add 30 grams of shot to one of each shape block. Add 60 grams of shot to one of each shape. Add 120 grams of each shape. Add 200 grams of shot to the remaining four blocks. Seal the holes in the shapes with glue. Fill the aquarium with water. Hypothesize which shape will sink the fastest. Using the stopwatch, drop each shape one at a time and record how long each takes to sink to the bottom of the tank. Create a graph to compare the differences in sinking rate, comparing weights and shapes of the objects.
For this experiment, you will need access to a swimming pool, a spring scale, fishing line, leader line, fishing swivels, graph paper, spherical objects of various sizes (oranges, softballs, grapefruits and so on), circular objects (CDs, plates, Frisbees and so on), rectangular shapes (blocks, bricks, boxes and so forth) and irregularly shaped objects. All of these objects should be waterproof and be naturally sinking objects. Weigh each object you decide to use. Hypothesize which objects will cause the most drag. Tie fishing line around each object you choose and attach a swivel hook to each. Add a leader line to the spring scale. Attach the swivel hook of one of the items to the spring scale. Put the object in the pool. Walk from one side of the pool to the other, pulling the object while it is submerged. Record the force of the object as measured by the spring scale. Repeat the procedures for all the items you chose. Create a graph of the data. Which objects caused the most drag?
Build four different hull shapes from a soft wood, such as pine. Each hull should have the same length and width. The width should not exceed 3 inches. For the experiment, you will need a 1- to 2-meter piece of 4-inch guttering, plastic gutter end-pieces, nails or hooks to fasten string to the hulls, string, a garden hose, a water source and a spring scale. Put a hook or nail in the middle of the top of each hull. Close off the ends of the gutter, leaving a small gap for the water outflow. Put the hose at the other end and add water. The gutter should be almost full and the flow of water steady. Hypothesize which hull type will have the greatest amount of drag. Put each hull in the gutter with the bow end toward the hose end. Attach a loop of string from the nail on the hull to the spring scale. Attach the other end of the spring scale to the opposite end of the gutter. Record the reading on the spring scale. Repeat the procedure for each hull. Compare the results with the initial hypothesis.