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Science & Engineering

Momentum Calculator

Calculate momentum p = mv and the result of a perfectly inelastic collision, including the kinetic energy lost.

Your inputs

Results

Velocity after sticking together

2 m/s

Total momentum (conserved)
6 kg·m/s
Momentum of object 1
6 kg·m/s
Kinetic energy lost (to heat, sound, deformation)
3 J

✓Exact calculation — rounded only for display

What this calculator does

Momentum is conserved in collisions. When objects stick together, kinetic energy is lost but momentum is not.

Formula and method

p = m v; inelastic: v_f = (m₁v₁ + m₂v₂) ÷ (m₁ + m₂); KE lost = KE_before − KE_after

Worked example

Calculated by this tool with its default inputs:

Inputs

  • Mass of object 1: 2 kg
  • Velocity of object 1: 3 m/s
  • Add a second object for a perfectly inelastic collision (they stick together): Yes
  • Mass of object 2: 1 kg
  • Velocity of object 2: 0 m/s

Results

  • Velocity after sticking together: 2 m/s
  • Total momentum (conserved): 6 kg·m/s
  • Momentum of object 1: 6 kg·m/s
  • Kinetic energy lost (to heat, sound, deformation): 3 J

How to read the results

Use signs for direction: opposite directions have opposite signs.

Assumptions and limitations

  • One-dimensional motion.

These are educational estimates. Electrical, structural and other safety-critical work must comply with local codes and be designed or checked by a qualified professional.

Questions

What about elastic collisions?

They conserve kinetic energy too and need a different formula; not modelled here.

Methodology and verification

Result type
Exact mathematical calculation (rounded only for display)
Formula version
1.0
Automated verification
3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
Editorial review
Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.

Privacy

Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy