Potential Energy Calculator
Calculate gravitational and elastic potential energy with explanations.
Potential Energy Formulas
Gravitational: PE = mgh (m in kg, g=9.8 m/s², h in m)
Elastic: PE = ½kx² (k in N/m, x in m)
Energy Conservation: PE + KE = constant (no friction)
PE Examples & Applications
| System | Type | Reference | Application |
|---|---|---|---|
| Ball on shelf | Gravitational | Ground level | Danger: mgh at fall |
| Compressed spring | Elastic | Equilibrium | Launch projectile |
| Water behind dam | Gravitational | Base of dam | Hydroelectric power |
Frequently Asked Questions
What is potential energy?
Stored energy due to position or configuration. Gravitational PE: energy from height. Elastic PE: energy in springs/stretched materials. Always relative to reference point.
What is gravitational potential energy?
PE = mgh, where m = mass (kg), g = 9.8 m/s² (gravity), h = height (m). Energy increases with mass and height. Measured in joules (J).
How does height affect gravitational PE?
Directly proportional. Double height = double PE. Object at sea level has less PE than at mountaintop (relative to ground below).
What is elastic potential energy?
PE = ½kx², where k = spring constant (N/m), x = displacement from equilibrium (m). Energy stored in springs, rubber bands, compressed materials.
What is the relationship between PE and gravity?
Work against gravity = change in PE. Lifting object increases PE. Lowering object decreases PE. PE depends on reference level.
Can potential energy be negative?
Yes, if reference point is chosen above object. PE = mgh can be negative if h < 0. Only differences in PE matter physically.
How is potential energy converted to kinetic energy?
As object falls, PE decreases and KE increases. Total mechanical energy (PE + KE) conserved if no friction. At bottom: all KE, no PE.
What is the relationship between PE and work?
Work done on object = change in PE. Lifting (positive work) increases PE. Gravity does negative work, decreasing PE.
How does spring constant affect elastic PE?
Stiffer spring (larger k) stores more PE for same compression. PE depends on k², so doubling k quadruples stored energy.
What are practical examples of potential energy?
Water behind dam (gravitational—powers hydroelectric). Compressed gas in balloon (elastic). Object on shelf (gravitational). Wound clock spring (elastic).
Why does PE depend on reference level?
Gravitational PE is relative. Can set h=0 at any point. Only PE differences between positions matter. Gravity and kinetic energy are independent of reference.
How do I solve PE problems?
Identify type (gravitational or elastic). Choose reference level. Measure mass/spring constant and height/compression. Use PE = mgh or PE = ½kx².