A rainbow of mucus and phlegm. As far as color goes, mucus is typically clear. But when the immune system sends white blood cells into the nose to fight off infection, they contain a greenish enzyme that shades the substance yellow or green.These are the same tones mucus takes on when it dries and clumps into boogers.s far as color goes, mucus is typically clear. But when the immune system sends white blood cells into the nose to fight off infection, they contain a greenish enzyme that shades the substance yellow or green. These are the same tones mucus takes on when it dries and clumps into boogers.
#3. Sandy_221. I think if the object that is acted upon is on the the X-Y plane, for example, then an applied force can't be considered a normal force if the former is in the same plane as the latter. In order for an applied force to be a normal force it has to be on the Z plane. Is this right? What do you think, guys?
A force in mechanics is a concept that has both a size and a direction. The net force acting on an object is the sum of the forces onto the object, taking into account both their sizes, and their directions. For example, if an object has two forces acting on it, with equal sizes but in opposite directions, then the net force will be zero (technically: a null vector). If instead the forces are of equal size and in the same direction, then the net force is equal to twice either force.