energy formulas and interpretation
Mechanical energy combines energy of motion and position.
The calculator reports kinetic, potential, and total energy together.
How to use the energy calculator
- Choose a model: Select the relationship matching the problem.
- Choose the unknown: Select the quantity to calculate.
- Enter values: Enter all known values with matching units and signs.
- Calculate: Review the result, formula, units, and direction.
Formula and variables
Mechanical energy is the sum of kinetic and gravitational potential energy.
E = ½mv² + mgh- m — Mass
- Object mass (kg)
- v — Velocity
- Object speed (m/s)
- h — Height
- Height above reference (m)
Mechanical energy example
A 2 kg object moves at 10 m/s at zero height.
- Mass
- 2 kg
- Speed
- 10 m/s
- KE = ½ × 2 × 10²
- KE = 100 J
Result: Mechanical energy is 100 J.
At zero reference height, all entered mechanical energy is kinetic.
Understanding your results
Interpreting the result
The total is relative to the chosen zero-height reference.
Assumptions
- The selected equation represents the physical system.
- Inputs use a consistent reference direction.
- Values are converted through coherent SI units.
Limitations
- Vector components must be resolved along a common axis.
- External forces or energy losses are not added automatically.
- Results depend on the accuracy of entered measurements.
Common mistakes
- Mixing incompatible units.
- Dropping negative signs that represent direction.
- Using weight where mass is required.
- Entering a zero divisor.
Practical use cases
Physics problems
Check classroom, laboratory, and mechanics calculations.
Practical estimates
Estimate motion, forces, and energy for real systems.
Frequently asked questions
Can a result be negative?
Yes. For directional quantities, the sign indicates direction relative to the chosen positive axis.
Should I use SI units?
The interface can convert supported units, while the formulas are evaluated through coherent SI units.
Sources and review
- SI Brochure, 9th edition — BIPM. Accessed 2026-07-11.
- Special Publication 811 — NIST. Accessed 2026-07-11.
Reviewed 2026-07-11.