IMPULSE On a secret mission… … to change equilibrium states!

EXTENSION to ROTATIONS Translation concepts: Mass Linear velocity Linear momentum Force Impulse equation Equivalent Rotation concepts: ??? (define it)

EXTENSION to ROTATIONS Translation concepts: Mass Linear velocity Linear momentum Force Equivalent Rotation concepts: Moment of inertia (mass and its distribution relative to the axis of rotation) Angular velocity Angular momentum Torque

HOW DOES IT WORK? EQUILIBRIUM IN TRANSLATIONS The ability of an object to rest depends on its mass: Inertia is measured by mass. Symbol for mass: m Mass is a scalar. EQUILIBRIUM IN ROTATIONS The ability of an object to be put into rotations (from rest) depends on mass and mass distribution: Inertia is measured by moment of inertia. Symbol for moment of inertia: I Moment of inertia is a scalar.

HOW DOES IT WORK? EQUILIBRIUM IN TRANSLATIONS Once moving, the ability of an object to stay in uniform linear motion depends on its linear momentum: Inertia is measured by linear momentum. Symbol for linear momentum: p Linear momentum is a vector. EQUILIBRIUM IN ROTATIONS Once moving, the ability of an object to stay in uniform rotational motion depends on its angular momentum: Inertia is measured by angular momentum. Symbol for angular momentum: L Angular momentum is a vector.

HOW DOES IT WORK? EQUILIBRIUM IN TRANSLATIONS Equation for linear momentum: p = m∙v Linear momentum is a vector. In one dimension (1D), vector directions are given by “+” or “-”, “up” or “down”, and by (opposite) cardinal points. EQUILIBRIUM IN ROTATIONS Equation for angular momentum: L = I∙ω Angular momentum is a vector. In rotational motion, the direction of vectors is said to be “clockwise” or “counterclockwise.”

HOW DOES IT WORK? AGENTS IN TRANSLATIONS To produce a change between equilibrium states, impulse must be produced. In translations, impulse depends on force and interaction time: I = F·Δt Force is a push or a pull in a direction. AGENTS IN ROTATIONS To produce a change between equilibrium states, impulse must be produces. In rotations, impulse depends on torque and interaction time: I = τ∙Δt Torque is force applied with leverage – force applied at a distance from the axis of rotation.

EXTENSION to ROTATIONS TRANSLATION CONCEPTS: ROTATION CONCEPTS:

THE END © Lilian Wehner