Lever arm

Definition

The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force. It is a crucial factor in determining the torque produced by a force.

5 Must Know Facts For Your Next Test

1. The magnitude of torque is calculated as the product of the force and the lever arm: $\tau = rF\sin(\theta)$.
2. A longer lever arm results in greater torque for a given force.
3. The lever arm is always perpendicular to the line of action of the force.
4. If multiple forces act on an object, each has its own lever arm contributing to net torque.
5. In rotational equilibrium, the sum of all torques acting on an object is zero.

Review Questions

• How does increasing the length of the lever arm affect torque?
• What is the relationship between lever arm and angle when calculating torque?
• In what condition will an object be in rotational equilibrium concerning torques?

Related terms

Torque:

A measure of how much a force acting on an object causes that object to rotate. It is calculated as $\tau = rF\sin(\theta)$.

Axis of Rotation:

An imaginary line around which an object rotates or spins.

Rotational Equilibrium:

A state where the sum of all torques acting on a system is zero, resulting in no angular acceleration.