you test weather charcoal helps purify water or not you design a filter that contains charcoal and run water from a nearby stream through the filter after ward you test the water for contamination what is the independent variable and the dependent variable

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane

An ideal polarizer with its transmission axis rotated 30 degrees to the vertical is placed in a beam of unpolarized light of intensity 10w/m^2. after passing through the polarizer, what is the intensity of the beam? a. 8.7 w/m^2 b. 7.5 w/m^2 c. 5.0 w/m^2 d. 10 w/m^2 e. 2.5 w/m^2

How can waves travel through ground?