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.
Remember, a force is either a push or pull. The 6 are: normal force; applied force; frictional force; tension force; spring force; resisting force; Let's investigate how these forces can be seen in our lives. Normal Force. A book resting on a table has the force of gravity pulling it toward the Earth. But the book is not moving or accelerating, so there must be opposing forces acting on the book. This force is caused by the table and is known as the normal force.