Work, Energy, and Power

Study Notes

Work

Definition: Work is the transfer of energy from one object to another through a force applied over a distance.
Formula: W = F × d × cos(θ)
- W: work done
- F: force applied
- d: distance over which the force is applied
- θ: angle between the force and displacement vectors
Units: Joules (J)
Types of work:
- Positive work: force and displacement are in the same direction
- Negative work: force and displacement are in opposite directions
- Zero work: force and displacement are perpendicular

Energy

Definition: Energy is the ability to do work.
Types of energy:
- Kinetic energy (K): energy of motion
  - Formula: K = 1/2 × m × v^2
    - m: mass
    - v: velocity
- Potential energy (U): energy of position or stored energy
  - Formula: U = m × g × h (gravitational potential energy)
    - m: mass
    - g: acceleration due to gravity
    - h: height
- Thermal energy (Q): energy of heat
- Electrical energy (E): energy associated with electric charges
- Chemical energy (E): energy stored in chemical bonds
Law of conservation of energy: energy cannot be created or destroyed, only converted from one form to another

Power

Definition: Power is the rate at which work is done or energy is transferred.
Formula: P = W / t
- P: power
- W: work done
- t: time over which the work is done
Units: Watts (W)
Types of power:
- Instantaneous power: power at a given instant
- Average power: power over a period of time
Examples of power:
- Mechanical power: power transmitted through mechanical systems
- Electrical power: power transmitted through electrical circuits

Description

Understand the fundamental concepts of work, energy, and power in physics, including their definitions, formulas, and units. Learn about the different types of work, energy, and power, and how they relate to each other.