Biophysics For Dummies

Chapter 5

Sitting with Couch Potatoes –– Static Equilibrium

In This Chapter

Talking translational equilibrium

Ruminating on rotational equilibrium

Forming static equilibrium of rigid bodies

A static object isn’t moving — it has no linear velocity and no angular velocity. An object in static equilibrium has no linear acceleration, no angular acceleration, and no motion. For example, while you’re reading this biophysics book, your head isn’t moving and it’s in static equilibrium. Even though your head isn’t moving, several interesting biophysical things are going on, such as a multitude of electrical signals is going into the brain from your five senses, thoughts are racing through your brain as you think, a multitude of signals is leaving your brain to control your body, blood is flowing through your brain supplying energy, and forces are pulling your head in different directions so you can balance it on your neck and keep it in static equilibrium.

In this chapter, I discuss the static equilibrium of biological systems composed of rigid bodies, meaning the objects in the biological system won’t break or deform under the forces acting on them. For example, my kitchen table is a rigid ...