The air is partially removed at the upper part of the tube and the valve is closed. The height of the water above its pool surface is 0.7 m. The height of the liquid above its pool surface is 0.33 m. The difference in the heights of the pool surfaces is 0.22 m. Required:
Find the density of the unknown liquid.

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

Energy is the ability to do work which measures what

Which of the following is part of the explanation or description of electromagnetic waves? (select all that apply) a. electrically charged molecules in a medium transfer their energy to nearby electrically charged molecules. b. a changing electric field causes a changing magnetic field. c. magnetic molecules in a medium transfer their energy to nearby magnetic molecules. d. a changing magnetic field causes a changing electric field.