Gravity & Astronomy Calculators
Gravity, orbit, escape-velocity, and pendulum calculators for planetary and classical systems.
Tools in Gravity & Astronomy Calculators
Formula tools for repeated physics work, unit checks, and setup examples.
Gravitational Force Calculator
Calculate gravitational force between two masses at a given separation.
Orbital Velocity Calculator
Calculate circular orbital velocity and orbital period from mass and radius.
Escape Velocity Calculator
Calculate escape velocity for a planet, moon, or star.
Pendulum Calculator
Calculate simple pendulum period and frequency from length and gravity.
Recommended Tools In This Topic
Start with these calculators when you need a related formula, unit, or worked-example check in this physics topic.
Formula Guide
Formulas, units, examples, and limits
Formula scope
- Gravity pages use F = G*m1*m2/r^2, v_orbit = sqrt(GM/r), and v_escape = sqrt(2GM/r).
- Pendulum timing uses T = 2*pi*sqrt(L/g) and f = 1/T for small-angle motion.
- Orbit and gravity formulas depend strongly on radius measured from the center of the body.
Variables and units
- Mass in kg, radius and separation in m, gravitational constant in N*m^2/kg^2.
- Velocity in m/s, period in s, force in N, local gravity in m/s^2.
- Pendulum length in m; frequency in Hz; Earth-g comparisons dimensionless.
Worked example
Pendulum timing on Earth
- 1For L = 1.2 m and g = 9.80665 m/s^2, compute T = 2*pi*sqrt(1.2/9.80665).
- 2Result: T is about 2.20 s and f is about 0.455 Hz.
- 3Use a smaller-angle assumption before comparing with a lab timing measurement.
Gravity and astronomy tools often fail when altitude is entered where center-to-center radius is required.
Common limits and checks
- Circular-orbit formulas are baselines for ideal two-body motion.
- Escape velocity ignores atmosphere, thrust profile, rotation, and mission trajectory.
- Simple pendulum timing assumes small swings and negligible pivot friction.
Gravitational Force Calculator
Calculate gravitational force between two masses at a given separation.
Orbital Velocity Calculator
Calculate circular orbital velocity and orbital period from mass and radius.
Escape Velocity Calculator
Calculate escape velocity for a planet, moon, or star.
About Gravity & Astronomy Calculators
Gravity and astronomy calculators tie together universal gravitation, orbital motion, escape conditions, and simple periodic systems like pendulums. The tools here focus on repeated physics workflows rather than broad textbook coverage.
Each tool is designed to reduce equation setup time while keeping the result transparent enough to support homework checks, lab work, or engineering back-of-the-envelope estimates.
Why these formulas belong together
Users usually arrive with a cluster of closely related questions. Someone solving projectile motion may also need velocity or free-fall results, and someone working on RC timing may also need Ohm's law or voltage-divider outputs.
Grouping these calculators by topic helps you move between related formulas without losing the physics context, whether you are comparing motion, circuits, heat, waves, fluids, or gravity problems.
Gravity & Astronomy Calculators FAQ
Use this page when you know the subject area but still need the right formula tool. Jump straight to a tool when you already know the exact calculation.
Switch topics when the variables or formula family change, such as moving from motion to circuits or from heat to gases.
No. These calculators help with setup and checking, but they should not replace course materials, lab guidance, or engineering review when those are required.
Explore related Physics topics
Start with the topic that matches your calculation, then use a related topic when the problem expands into another formula set.