Can someone me with this really quick

Apple juice is a homogeneous mixture. That means when you look through it, you can't see anything but  a liquid with your naked eye. The color is constant. Then how do you know there is something else in there? The color gives you the hint you need. Pure water is colorless in liquid form.

The salad dressing might be a solution and it can be made to temporarily mix when you shake it, but it will soon separate into oil and a water based acid usually vinegar.

Filtering wouldn't affect the apple juice. Whatever is in there will go through filter paper. It's like using a screen with 1 inch squares: only the largest stones would be filtered out.

Filtering might take out some of the particles in the oil / acid mixture but likely on the herbs put in. I'm not sure you should say no effect on either really.

wavelength divides in half and speed stays the same.