How to Calculate Gravitational Field
What is Gravitational Field?
Gravitational field strength measures the gravitational force per unit mass at a location. It's fundamental to understanding celestial mechanics and tidal forces.
Formula
The calculator applies g = GM / r²
- GM
- GM value — Variable used in the calculation
- g
- GM / r² — GM / r²
Step-by-Step Guide
- 1Enter the source mass and distance from its center
- 2The calculator applies g = GM / r²
- 3Results show gravitational field strength
Worked Examples
Input
M = 5.972 × 10²⁴ kg (Earth), r = 6.378 × 10⁶ m (surface)
Result
g ≈ 9.81 m/s²
Standard gravity at sea level
Common Mistakes to Avoid
- ✕Using altitude above surface instead of distance from center
- ✕Confusing gravitational field with gravitational potential
Frequently Asked Questions
Does gravitational field strength vary with mass of test object?
No, it's independent of test mass. A feather and hammer experience the same field.
Why does gravity follow an inverse square law?
Gravity spreads from a point source in three dimensions; field strength decreases as area increases (4πr²).
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