Power
Also known as: P, wattage
The rate at which work is done or energy is transferred, measured in watts (joules per second). Power determines how quickly engines, motors, and electrical devices can deliver energy.
💡 Intuition
How fast you use or produce energy. A powerful engine does work quickly.
Core Idea
Power measures how quickly energy is transferred — the same work done faster requires more power.
Formal View
🔬 Example
🎯 Why It Matters
Power determines how quickly engines, motors, and electrical devices can deliver energy. It is the key specification for car engines, light bulbs, and power plants, and governs electricity bills and energy efficiency ratings.
⚠️ Common Confusion
A small motor can do the same work as a big motor—it just takes longer.
💭 Hint When Stuck
When solving a power problem, first determine whether you know work and time or force and velocity. Then use P = W/t if you have work done over a time interval, or P = Fv if you have a constant force and velocity. Finally, check that your units are in watts (joules per second).
Related Concepts
Next Steps
How Power Connects to Other Ideas
To understand power, you should first be comfortable with work and energy. Once you have a solid grasp of power, you can move on to electrical power.
Go Deeper
Frequently Asked Questions
What is Power in Physics?
The rate at which work is done or energy is transferred, measured in watts (joules per second).
Why is Power important?
Power determines how quickly engines, motors, and electrical devices can deliver energy. It is the key specification for car engines, light bulbs, and power plants, and governs electricity bills and energy efficiency ratings.
What do students usually get wrong about Power?
A small motor can do the same work as a big motor—it just takes longer.
What should I learn before Power?
Before studying Power, you should understand: work, energy.
🧪 Interactive Playground
Drag to explore. Click to commit changes.