Archimedes Principle and Buoyancy Lab Activities
Activity 1
1. Set up the water bath in a beaker and ringstand as shown by instructor.
2. Hang the cylinder and the bucket from the spring scale. Record the weight of both pieces as shown on the spring scale.
Weight of both pieces (cylinder and bucket)______N
3. Separate the Archimedes Principle apparatus, and hang the cylinder from the bottom of the bucket.
4. Lower the spring scale until the top surface of the cylinder is just below the surface of the water. Measure the weight of the apparatus. It will appear as though the cylinder and bucket weigh less in water.
5. Keeping the cylinder submerged, slowly fill the bucket with water until the weight of the system returns to what was measured in #2 above.
Question: How full did the bucket have to be before the weight returned back to the original value?______-
Briefly explain what this means in terms of Archimedes Principle______
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Activity 2
1. Fit the cylinder inside the bucket . Submerge both cylinder and bucket in the beaker of water until the water just covers the top of the apparatus.
2. Record the weight of the cylinder and bucket
Weight of Cylinder and bucket while submerged______N
3. Hang the cylinder from the ring of the bucket. Submerge both in the beaker of water. Since the cylinder no longer fills the bucket and the bucket is now submerged, it naturally fills completely with water.
4. At this point in the experiment it is often assumed that the cylinder, bucket and water inside the bucket add up to a weight greater than the weight attained in #2, when the cylinder was inside the bucket. However, the equilibrium evidenced by the spring scale proves that they weigh the same
Explain why this is so.______
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Activity 3
1. Verify Archimedes principle by using a graduated cylinder to determine how much water is displaced by a small metal cylinder. Read the level of the water before and after the object is submerged and determine the amount of water displaced. Assume the density of water to be 1.0 g/cm3 or 1000 kg/m3, calculate the weight of the water that is displaced. Use the scale to determine the mass of the metal cylinder and its apparent mass when submerged in the water. Find the buoyant force supplied by the water and compare to the weight of the water displaced.
Buoyant Force______Weight of water displaced______
2. Use the mass of the cylinder found in #1 and the volume of the water displaced to determine the density of the metal cylinder.
3. Determine the radius and length of the metal cylinder and calculate the density. Remember, the volume of a cylinder =L πr2. Compare the results of the two methods. Find the percent difference.
4. Verify Archimedes principle for the small wood block. Read the level of the water before and after the object is placed in the water. This change in volume is equal to the volume of wood under the water, Vu. Using the density of water given above, calculate the weight of the wood. Also use Archimedes principle to determine the density of the wood sample.
Activity 4
1. Suppose you are on a ship in a canal lock. If you throw a ton of bricks overboard into the canal lock, will the water level in the canal lock go up, go down, or stay the same.
Prediction for water level in canal lock______
2. Float a boat(part of a plastic bottle) loaded with cargo ( a few 50g masses) in a beaker filled with water. Mark and label the water levels on the container and on the sides of the boat. Remove some of the masses from the boat and put them in the water. Mark and label the new water levels.
Questions: What happens to the water level on the side of the boat when you place the cargo in the water?
What happens to the water level in the container when you place the cargo in the water? Explain what happens
What will happen to the water level in the canal lock when the bricks are thrown overboard?