# Torque and Rotational Statics

## Understanding Torque

• Torque is a measure of the force that can cause an object to rotate around an axis.
• It is a vector quantity, typically measured in Newton metres (Nm).
• Torque is calculated by multiplying the force (F) causing the rotation by the distance (r) from the axis of rotation to the point where the force is applied.
• The formula for torque is τ = rFsinθ, where τ represents the torque, r is the distance, F is the force, and θ is the angle between the force and the lever arm.

## Rotational Statics

• In rotational statics, we study objects that are in rotational equilibrium, which means they are either at rest or rotating at a constant angular velocity.
• When an object is in rotational equilibrium, the net torque acting on it is zero.
• This gives rise to the conditions for equilibrium: The net force and the net torque on an object must both be zero for it to be in equilibrium.

## Key Concepts of Torque

• The direction of torque is determined by the right-hand rule. If you curl the fingers of your right hand from the direction of the lever arm to the direction of the force, your thumb will point in the direction of the torque.
• Maximum torque is achieved when the force is applied perpendicular to the lever arm (θ = 90°), while the torque is zero when the force is applied parallel to the lever arm (θ = 0° or 180°).

## Torque and Real World Applications

• Understanding torque is vital for the design of many mechanical systems such as seesaws, door handles, and wrenches.
• Understanding rotational statics is important for the stability of structures such as bridges and buildings.

## Torque and Rotational Statics Practice Problems

• Practice problem-solving involving torque and rotational statics to solidify your understanding.
• Try working on problems involving objects at rest, objects rotating at a constant velocity, and scenarios where you have to calculate the net torque.
• Keep practising and revisit key concepts as needed for mastery.

By gaining a solid grasp of torque and rotational statics, you’ll be ready to tackle a variety of physics problems dealing with rotational motion and equilibrium.