SUMMARY
Session Goals
Define key terms: Work, Energy, Mechanical (potential, kinetic), Power.
Relate work to force and distance.
Outline the work-energy theorem.
State the law of conservation of energy.
Explain conversion between potential and kinetic energy.
State SI units of energy (Joules) and power (Watts).
Integrate concepts of acceleration, force, inertia, momentum, impulse, work, energy, and power for stationary and moving objects.
Perform calculations involving force, acceleration, momentum, impulse, work, energy, and power.
Work
Definition of work in physics: ability to move an object against a force.
Work formula: W = Fd; changing an object's energy condition requires movement.
Work is done against forces (e.g., gravity) during speed changes or position changes.
Measuring Work
Unit of work: Joule (J), where 1 Joule = 1 Newton x 1 meter.
To measure work, calculate using W = F imes d where force is in Newtons and distance in meters.
Power
Definition: power is work done per unit time; formula: P = rac{W}{t}.
Unit of power: Watt (W), where 1 Watt = 1 Joule/1 second.
Energy
Definition: energy is the capacity to do work.
Forms of energy include mechanical, potential, kinetic, and more
Energy is measured in Joules; work transfers energy between systems.
Mechanical Energy
Mechanical energy = energy of motion and position, consisting of:
Potential Energy (PE): energy due to position.
Kinetic Energy (KE): energy due to motion.
Potential Energy (PE)
Stored energy based on an object's position influenced by external forces.
Example: stretching an elastic band stores potential energy.
Kinetic Energy (KE)
Energy of a moving object, capable of performing work.
Formula: KE = rac{1}{2} mv^2; dependent on mass and velocity.
Conservation of Mechanical Energy
Total mechanical energy (PE + KE) remains constant unless acted on by external forces.
Example: As an object falls, its PE decreases while its KE increases, keeping total mechanical energy constant.
Summary
Be able to define key physics concepts and perform calculations related to work, energy, and power. Understand their inter-relationships and applications in physical scenarios.