Chapter 4.2 - Angular Motion

Flashcards covering key concepts from Chapter 4.2 on Angular Motion, including definitions, laws, and formulas.

What is angular motion?

Angular motion refers to rotation and involves movement around a fixed point or axis.

What is an eccentric force?

An off-centre force applied outside the centre of mass.

What are the three axes around which angular motion can occur?

Transverse axis, sagittal axis, and longitudinal axis.

What causes angular motion?

Angular motion occurs as a result of a torque, which is a turning force.

How can torque be increased?

By increasing the size of the force or by applying the same force further from the axis of rotation.

What is the formula for calculating the moment of force/torque?

Moment of force/torque (Nm) = Force (N) x Perpendicular distance from the fulcrum (m).

What does Newton's first law state about a rotating body?

A rotating body will continue to turn about its axis of rotation with constant angular momentum unless an external rotational force (torque) is exerted upon it.

What does Newton's second law state about torque and angular momentum?

The rate of change of angular momentum is proportional to the torque causing it.

What is the significance of Newton's third law in angular motion?

When a torque is applied by one body to another, the second body exerts an equal and opposite torque.

What is angular displacement?

The smallest change in the angle between the starting and finishing points, measured in degrees and radians.

How is angular velocity defined?

The rotational speed of an object and the axis about which it is rotating; a vector quantity referring to angular displacement over time.

What is the formula for calculating angular acceleration?

Angular acceleration (rad/s²) = Change in angular velocity (rad/s) / Time taken (s).

What is moment of inertia?

The resistance of a body to angular motion, dependent on the mass and distribution of mass around the axis.

How does mass affect moment of inertia?

The greater the mass, the greater the resistance to change and moment of inertia.

How does the distribution of mass from the axis of rotation affect turning ease?

Closer mass to the axis makes turning easier, while greater distance increases moment of inertia.

What is angular momentum?

The quantity of rotation a body possesses, depending on moment of inertia and angular velocity.

What is the conservation of angular momentum?

Angular momentum stays constant unless an external torque acts upon it.