Description
Ideal no-drag projectile kinetic-energy fraction at the vertical apex, relative to launch, for nonzero launch speed.
A mechanics calculation needs a coordinate frame, sign convention, and consistent force, length, mass, and time units. Vector projections, local balance terms, and ideal motion equations describe particular parts of a physical model. They do not automatically establish all equilibrium conditions or the validity of the model.
Ideal no-drag projectile kinetic-energy fraction at the vertical apex, relative to launch, for nonzero launch speed.
When to use this tool
Use Projectile Apex Energy Fraction when you need this particular projection, balance, frame conversion, or ideal-model component from supplied physical quantities.
How to use the tool and how it works
- Enter horizontalSpeed, verticalSpeed. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read retainedKineticFraction, initialSpeedSquared. Use the output convention below.
Require horizontalSpeed^2+verticalSpeed^2>0 and return initialSpeedSquared as that sum and retainedKineticFraction=horizontalSpeed^2/initialSpeedSquared.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| horizontalSpeed | Horizontal Speed | Required. Finite number. |
| verticalSpeed | Vertical Speed | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| retainedKineticFraction | Retained Kinetic Fraction | Required. Finite number. |
| initialSpeedSquared | Initial Speed Squared | Required. Finite number. |
{
"input": {
"horizontalSpeed": 3,
"verticalSpeed": 4
},
"output": {
"retainedKineticFraction": 0.36,
"initialSpeedSquared": 25
}
}Limitations and assumptions
- This is the ideal drag-free projectile's kinetic-energy fraction at its apex. Speeds need one unit; no apex existence after launch, air resistance, or relativistic effect is checked.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Signed zero is exported as zero.
Alternative or Complementary methods
Use a complete force, motion, or energy model when a single contribution is insufficient. Check coordinate frames, idealizations, and dimensional consistency before combining calculated terms.
References
Similar or alternative tools
- Projectile Trajectory Apex Time Offset
For positive gravity return apexTime=verticalVelocity/gravity and timeUntilApex=apexTime-currentTime.
- Elastic Energy Strain One Mode
Return one linear elastic uniaxial mode energy, excluding plasticity and multiaxial coupling.