Energia e Lavoro (Energy and Work)
This page introduces the fundamental concepts of energy and work in physics, focusing on kinetic energy and the definition of work.
Kinetic Energy
The page begins by defining kinetic energy as the energy possessed by a body of mass m moving with velocity v.
Definition: Energia cinetica spiegazione semplice: Kinetic energy is given by the formula K = 1/2mv², where m is mass and v is velocity.
Highlight: Kinetic energy is always positive and cannot be negative.
Work
The concept of work is introduced as the transfer of energy through the application of a force.
Definition: Work is defined as W = F · Δs, where F is force and Δs is displacement.
The page emphasizes that work is a scalar product, meaning only the component of force parallel to the displacement contributes to work.
Vocabulary: Lavoro ed energia formule: W = |F| · Δs · cos(α), where α is the angle between force and displacement.
Different scenarios of work are presented based on the angle between force and displacement:
- When α = 0°, work is positive (W > 0)
- When 0° < α < 90°, work is positive (W > 0)
- When α = 90°, work is zero (W = 0)
- When 90° < α < 180°, work is negative (W < 0)
- When α = 180°, work is negative (W < 0)
Highlight: The direction of force relative to displacement determines whether work is positive (motor work) or negative (resistive work).
The page concludes by mentioning that work is measured in Joules [J] and provides examples of work done by constant forces and spring forces.
