What does e- in science mean

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?

What produces wave a)sound b) heats c)transfer of energy d)vibrations

How can a give a full method for the experiment of separating sand from water by filtration? 1-materials 2-steps 3-conclusion also for water and salt separated by the evaporation or distillation process