Skip to main content

Kinetic & Potential Energy

Science & Engineering

Ek=½mv² and Ep=mgh with real-world equivalents

Quick Answer

Kinetic & Potential Energy: Ek=½mv² and Ep=mgh with real-world equivalents. Ek = ½mv² — doubling speed quadruples the energy.

kg
m/s
Solve for KE
386.42 kJ

Calculation steps

  1. 1KE = ½ × m × v²
  2. 2v = 27.8 m/s = 100.1 km/h
  3. 3KE = 0.5 × 1000 × 27.8² = 386420.0 J
  4. 4Note: doubling speed quadruples energy — that is why speed kills.

Crash energy: speed vs mass

ScenarioMassSpeedKinetic energy
Car 1500 kg at 50 km/h1500 kg13.9 m/s145 kJ
Car 1500 kg at 100 km/h1500 kg27.8 m/s580 kJ
Car 1500 kg at 120 km/h1500 kg33.3 m/s832 kJ
Truck 10,000 kg at 60 km/h10000 kg16.7 m/s1.39 MJ
Pedestrian hit at 40 km/h—11.1 m/s~10% fatality risk
Pedestrian hit at 60 km/h—16.7 m/s~80% fatality risk
Energy grows with the square of speed: 100 km/h carries 4× the energy of 50 km/h, not 2×. Braking distance also scales with v². This quadratic relationship is why urban speed limits save so many lives — a pedestrian hit at 30 km/h usually survives; at 60 km/h usually not.

Was this tool helpful?

How to Use

  1. Enter known quantities: fill values and confirm units in the Kinetic & Potential Energy.
  2. Instant solution: unknowns solve live with the formula shown transparently.
  3. Use constant/material tables: standard physical constants and material data are listed on this page.
  4. Compare conditions: change inputs to compare scenarios.

Key Points

  • Kinetic & Potential Energy is a free online science & engineering tool — open and use, no sign-up.
  • All calculations run locally in your browser; your data never leaves the device.
  • Key capability: Ek=½mv² and Ep=mgh with real-world equivalents.
  • Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

Kinetic & potential energy

Ek = ½mv² — doubling speed quadruples the energy
Ep = mgh (g = 9.8 m/s²)
Equivalents: 1g TNT = 4184 J; 1 kWh = 3.6 MJ
Conservation: falling h meters converts mgh to ½mv², so v = √(2gh)

Example: 60kg runner at 10m/s → Ek = 3000 J ≈ 0.72g TNT.

FAQ

How do I use the Kinetic & Potential Energy?
Open the page and fill in the input fields — results update automatically. Ek=½mv² and Ep=mgh with real-world equivalents.
Are the results accurate?
Yes. Standard formulas and conversion factors are used and verified.
Is it free? Do I need to sign up?
Completely free. No registration, login or download required.
Does it work on mobile?
Yes. The responsive design works on phones, tablets and desktops.
Is my data saved?
No. Everything runs locally in your browser.

Related Tools

Related Guides

Source & Updates

Based on CODATA recommended constants and standard physics formulas. Last updated: 2025-07

Last updated:

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Maintained and periodically reviewed by the YiJianSuan editorial team — review process in ourEditorial Policy.

Cite this page: YiJianSuan. Kinetic & Potential Energy[EB/OL]. https://www.yijiansuan.com/en/c/science/kinetic

Results provided by this tool are for reference only and do not constitute professional advice.