What does background research mean if you were to use it for the science fair? is it the same as background information? ! sorry if i got the category wrong!

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

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

Which sound characteristic is not affected by the relative motion of an object