Basic Concepts
In a nutshell: Work transfers energy, and power measures how fast energy is transferred.
## Making Things Happen: Energy and Power
Physics isn't just about moving—it's about *making* things move! Work, energy, and power describe how you make things happen.
### Work
Work is done when a force moves something. It's calculated as:
\( W = Fd \cos\theta \)
where \( \theta \) is the angle between the force and the direction of movement.
### Energy
- **Kinetic Energy**: Energy of motion (\( KE = \frac{1}{2}mv^2 \))
- **Potential Energy**: Stored energy due to position (\( PE = mgh \))
### Power
Power is how quickly work is done:
\( P = \frac{W}{t} \)
### Why It Matters
Every time you climb stairs, pedal a bike, or charge your phone, you're dealing with work, energy, and power!
Examples
- Lifting a box onto a shelf requires work against gravity.
- A light bulb uses electrical power to produce light and heat.
Key terms
- Work
- A measure of energy transferred by a force.
- Power
- The rate at which work is done or energy is transferred.