1. Measure the diameter d of the bottom surface of the container.
2. Measure the height of water injection surface of cylindrical container h 1.
3. Measure the height h2 of the water surface after putting the potatoes (to ensure that the potatoes completely sink into the water surface).
4. Calculate the potato volume = 1/4 * d 2 * π * (H2-H 1).
B) similarly measure the volume of iron, weigh it, and then calculate it, and limit the number of words.