Free · Physics models
Signed Acceleration Relative to Local Gravity
Compare average velocity change over time to a chosen local gravitational acceleration, with a spherical-gravity estimate.
- Formula & worked example
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Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
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Formula and method
A velocity increase from 0 to 20 m/s over 2 s is one local g when local gravity is 10 m/s².
Local g = GM/r²; signed g multiple = (v1−v0)/(Δt local g).
Worked example
Enter these known values and leave the other values blank.
- Acceleration due to gravity (g)
- 10 m/s²
- Initial velocity (V==0==)
- 0 m/s
- Final velocity (V==1==)
- 20 m/s
- Time (t)
- 2 sec
- Mass (M)
- 1.018299 Earths
- g force
- 1 g
Assumptions and limitations
- The result is a signed ratio to the chosen local gravitational acceleration. It is not necessarily acceleration in units of standard Earth gravity.
- The velocity change divided by elapsed time is average acceleration. Negative values represent deceleration along the chosen axis.
- The separate GM/r² estimate assumes a spherical body and radius measured from its center. The constant uses G = 6.67430×10⁻¹¹ SI.
- The ratio does not compute an occupant’s proper acceleration or vector felt load. Free fall, rotation, support forces and multidirectional motion require a separate model.
- Mass and radius defaults are illustrative Earth scales; entering local gravity directly avoids treating those scales as precision geophysical data.
- Enter known quantities and leave the unknown blank. Editable quantities support inverse solutions and locks; inconsistent locked quantities are reported. Unit selectors convert the quantity independently of its display.
- Reviewed hash-pinned model correction: The result is a signed ratio to the chosen local gravitational acceleration. It is not necessarily acceleration in units of standard Earth gravity. The velocity change divided by elapsed time is average acceleration. Negative values represent deceleration along the chosen axis. The separate GM/r² estimate assumes a spherical body and radius measured from its center. The constant uses G = 6.67430×10⁻¹¹ SI. The ratio does not compute an occupant’s proper acceleration or vector felt load. Free fall, rotation, support forces and multidirectional motion require a separate model. Mass and radius defaults are illustrative Earth scales; entering local gravity directly avoids treating those scales as precision geophysical data. Enter known quantities and leave the unknown blank. Editable quantities support inverse solutions and locks; inconsistent locked quantities are reported. Unit selectors convert the quantity independently of its display.
Common questions
Is this always standard Earth g?
No. The result is relative to the chosen local gravitational acceleration, which can differ from standard gravity.
Does the ratio measure felt load?
No. A signed velocity-change ratio alone does not determine proper acceleration or the forces on an occupant.
How do I use the inverse calculation?
Clear the quantity you want to find and enter the remaining known values in their selected units. The model can only solve branches with enough independent information.
References
- NIST: Newtonian gravitational constant
- NIST CODATA physical constants
- Calculation definition and unit reference
Keep the hidden CODATA gravitational constant fixed by removing its unphysical inverse. Editing local gravity must infer mass or radius, never silently change G.