Science
Perfectly inelastic collision
Find the shared velocity and kinetic energy loss when two bodies stick together.
Calculators / Science / One-dimensional elastic collision
One-dimensional elastic collision calculator
Find both velocities after a perfectly elastic collision along one axis.
On this page
First final velocity-2m/s
Second final velocity3m/s
Initial kinetic energy17.5J
Calculator controls
How to calculate
Find both velocities after a perfectly elastic collision along one axis.
First final velocity =
((m1-m2)*u1+2*m2*u2)/(m1+m2) m/sSecond final velocity =
(2*m1*u1+(m2-m1)*u2)/(m1+m2) m/sInitial kinetic energy =
(m1*u1^2+m2*u2^2)/2 JWorked example
- First mass (kg): 2
- Second mass (kg): 3
- First initial velocity (m/s): 4
- Second initial velocity (m/s): -1
- First final velocity: -2 m/s
- Second final velocity: 3 m/s
- Initial kinetic energy: 17.5 J
Assumptions and limits
This is an ideal educational model. Enter quantities in the stated SI units; it does not certify equipment safety or real operating limits. Total momentum and kinetic energy are conserved; signed velocities use one common axis.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Find both velocities after a perfectly elastic collision along one axis. Use this model to compare masses and verify conservation laws, not to predict crash damage.
When this tool is useful
Use this model to compare masses and verify conservation laws, not to predict crash damage.
Understanding your inputs
| Input | Example |
|---|---|
First mass (kg) m1 | 2 |
Second mass (kg) m2 | 3 |
First initial velocity (m/s) u1 | 4 |
Second initial velocity (m/s) u2 | -1 |
Frequently asked questions
Which assumptions matter for this result?
This is an ideal educational model. Enter quantities in the stated SI units; it does not certify equipment safety or real operating limits. Total momentum and kinetic energy are conserved; signed velocities use one common axis.
How can I check the worked example?
Use the displayed example inputs in the stated formula. Keep each quantity in its labelled unit and compare the unrounded result before applying display rounding.