Equilibrium

Definition

Equilibrium occurs when all forces acting on an object are balanced, resulting in no net force and no acceleration. In static equilibrium, the object is at rest, and in dynamic equilibrium, it moves with constant velocity.

5 Must Know Facts For Your Next Test

1. For an object to be in static equilibrium, the sum of all forces and the sum of all torques acting on it must be zero.
2. Newton's First Law states that an object in equilibrium will remain at rest or move with constant velocity unless acted upon by an external force.
3. The condition for translational equilibrium is given by $\sum \vec{F} = 0$.
4. The condition for rotational equilibrium is given by $\sum \tau = 0$, where $\tau$ represents torque.
5. In problems involving static equilibrium, both the magnitude and direction of forces must be considered to ensure balance.

Review Questions

• What conditions must be met for an object to be in static equilibrium?
• How does Newton's First Law relate to the concept of equilibrium?
• What equations represent the conditions for translational and rotational equilibrium?

Related terms

Torque: A measure of the force that can cause an object to rotate about an axis. It is calculated as the product of force and lever arm distance.

Net Force: The vector sum of all forces acting on an object. If it equals zero, the object is in translational equilibrium.

Newton's First Law: A principle stating that an object will remain at rest or move with a constant velocity unless acted upon by a net external force.