Pivot point

Definition

A pivot point is a fixed point around which a body rotates or balances. It plays a crucial role in determining whether a system is in static equilibrium.

5 Must Know Facts For Your Next Test

1. The sum of torques about the pivot point must be zero for static equilibrium.
2. A pivot point can be used to simplify the analysis of forces and torques acting on a system.
3. Choosing different pivot points can lead to different torque equations, but all should satisfy the condition for equilibrium.
4. The location of the pivot point affects the lever arm distance for each force applied.
5. In problems involving beams or levers, the pivot point is often where supports or hinges are located.

Review Questions

• Why is it important for the sum of torques about the pivot point to be zero in static equilibrium?
• How does changing the location of the pivot point affect your analysis of a system?
• What role does the lever arm distance play when calculating torque about a pivot point?

Related terms

Torque:

A measure of how much a force acting on an object causes that object to rotate, calculated as $\tau = rF\sin(\theta)$ where $\tau$ is torque, $r$ is lever arm distance, $F$ is force, and $\theta$ is the angle between force and lever arm.

Static Equilibrium:

A state where an object remains at rest, with both net force and net torque equal to zero.

Lever Arm:

The perpendicular distance from the axis of rotation (pivot point) to the line of action of the force.