Potential Energy

📚 Key Concepts of Potential Energy

🔹 Real-Life Example

Water stored in a dam at height has gravitational potential energy — when released, it can turn turbines and generate electricity.

A stretched bow stores elastic potential energy that can launch an arrow.

A book on a shelf has potential energy that converts to kinetic energy when it falls.

Potential Energy: The energy possessed by an object due to its position or configuration.

🧪 Important Formulas

🔸 Gravitational Potential Energy

PE = mgh

Where:

PE = Potential energy (J)
m = Mass of object (kg)
g = Acceleration due to gravity (9.8 m/s²)
h = Height above reference level (m)

🔹 Types of Potential Energy

1. Gravitational Potential Energy

Due to position in a gravitational field
Examples: Water in elevated tank, book on shelf

2. Elastic Potential Energy

Due to deformation of elastic materials
Examples: Stretched spring, compressed rubber ball

🔍 Advanced: Reference Level

Potential energy is relative — we choose a reference level (usually the ground) as zero potential energy. The actual value depends on this choice, but energy differences remain the same.

🔹 Applications of Potential Energy

Hydroelectric power: Water at height → electricity
Pumped storage: Store energy by pumping water uphill
Springs: Store and release energy in mechanical systems

Solution: PE = mgh = 10 × 9.8 × 5 = 490 J

Potential energy is directly proportional to height:

PE ∝ h

So, doubling the height doubles the potential energy.

📌 Potential energy becomes 2 times.

PE = mgh

The object at 6 m has greater height, so:

PE<sub>6m</sub> = m × g × 6 = 2 × PE<sub>3m</sub>

📌 The object at 6 m has twice the potential energy compared to the one at 3 m.