How to Calculate Orbital Velocity
What is Orbital Velocity?
Orbital velocity is the speed needed to maintain a circular orbit at a given altitude. It depends on the central body's mass and orbital radius.
Formula
The calculator applies V_orbit = √(GM / r)
- GM
- GM value — Variable used in the calculation
Step-by-Step Guide
- 1Enter the central body's mass, orbital radius, and gravitational constant
- 2The calculator applies V_orbit = √(GM / r)
- 3Results show circular orbital speed
Worked Examples
Input
M = 5.972 × 10²⁴ kg (Earth), r = 6.378 × 10⁶ m (surface)
Result
V_orbit ≈ 7,900 m/s
First cosmic velocity
Common Mistakes to Avoid
- ✕Confusing orbital velocity with escape velocity
- ✕Using altitude instead of orbital radius
Frequently Asked Questions
Why doesn't the Moon fall toward Earth?
It's continuously falling but moving sideways at orbital velocity; gravity continuously redirects its path.
Do all orbits have the same velocity?
No, velocity decreases with orbital radius following V ∝ 1/√r; higher orbits move slower.
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