AP BIOLOGY

Detailed explanation-1: -When all the forces that act upon an object are balanced, then the object is said to be in a state of equilibrium. The forces are considered to be balanced if the rightward forces are balanced by the leftward forces and the upward forces are balanced by the downward forces.

Detailed explanation-2: -If the size and direction of the forces acting on an object are exactly balanced, then there is no net force acting on the object and the object is said to be in equilibrium.

Detailed explanation-3: -Conditions of Equilibrium An object is in equilibrium in a reference coordinate system when all external forces (including moments) acting on it are balanced. This means that the net result of all the external forces and moments acting on this object is zero.

Detailed explanation-4: -When all the forces acting upon an object balance each other, the object will be at equilibrium; it will not accelerate. (Note: diagrams such as the one above are known as free-body diagrams and will be discussed in detail in Lesson 2.)

Detailed explanation-5: -Examples include a weight suspended by a spring or a brick lying on a level surface. An equilibrium is unstable if the least departure produces forces that tend to increase the displacement. An example is a ball bearing balanced on the edge of a razor blade.