​​​​​​​ Energy, Work, and Power

These three fundamental concepts are key to understanding physics, machines, and everyday life.

🔋 1. Energy

Energy is the ability to do work or cause change. It exists in many forms and cannot be created or destroyed, only transformed.

🧪 Types of Energy:

• Kinetic Energy – energy of motion (e.g., a moving car)

• Potential Energy – stored energy due to position (e.g., a rock on a hill)

• Thermal Energy – heat

• Chemical Energy – stored in food or fuel

• Electrical Energy – from moving electrons

• Nuclear Energy – from the nucleus of atoms

📏 Energy Unit:

• Joule (J) is the standard unit of energy.

⚙️ 2. Work

Work is done when a force moves an object over a distance.

📘 Formula:

Work (W)=Force (F)×Distance (d)\text{Work (W)} = \text{Force (F)} \times \text{Distance (d)}

• Work is only done if there is movement in the direction of the force.

• If you push a wall and it doesn’t move, no work is done.

📏 Work Unit:

• Also measured in Joules (J)

• 1 Joule = 1 Newton × 1 meter

🧠 Example:

• Lifting a box from the ground uses force over a distance → work is done.

⚡ 3. Power

Power is the rate at which work is done or energy is transferred.

📘 Formula:

Power (P)=Work (W)Time (t)\text{Power (P)} = \frac{\text{Work (W)}}{\text{Time (t)}}

• Power tells us how fast energy is used.

📏 Power Unit:

• Watt (W)

• 1 Watt = 1 Joule per second

• Kilowatt (kW) = 1000 Watts

🧠 Example:

• A person running up stairs quickly uses more power than someone walking.

🧠 Summary Table:

These concepts explain how machines function, how humans use energy, and how systems transfer force and motion in the physical world.