Green or Dark Yellow Phlegm. A thick and dark yellow phlegm may be a sign of a viral or bacterial infection, sinus infection, or lower respiratory tract infection. Typically, this occurs when the immune system sends white blood cells, known as neutrophils, to the area of infection.ink Phlegm. Pink-colored phlegm is anything but pretty. Coughing up pink phlegm is an indicator of pulmonary edema, also known as fluid in the lungs. It can also be a sign of bleeding when seen in small amounts, which show up as a stain or streak.
The normal force, which is the force that supports the weight of an object on a surface, acts in the opposite direction of gravity. Most often, we see this with objects at rest on a horizontal surface, like a book on a table or someone standing on a floor.
Â· just now. Report Abuse. A normal force is a perpendicular force; typically the force is perpendicular to a surface and pointing into it, but it doesn't have to be. In the friction equation F = kN, the normal force is N = W cos(theta) where theta is the incline of the surface where the friction is.W = mg is the weight of the body m.riction between the box and the surface is _________________. The normal force on the box is ______________. Net force acting on the box between A and B is __________________. Average speed of the box between points A and B is ____________.