To test how fertilizer affects aquatic animals, a student prepared four identical containers with water fleas. The student then added different amounts of fertilizer mixed with distilled water to three of three of the containers and distilled water alone to one of the containers. What factor is being tested in this experiment?

Explain earth's motion, using the terms "precession" and "rotation" in your answer.

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.

The largest observatory complex in the world is on mauna kea, the tallest mountain on earth. what are some factors astronomers consider when selecting an observatory site? don’t forget practical ones. should astronomers, for example, consider building an observatory on denali (mount mckinley) or mount everest?