1. What is Surface Gravity?

Surface gravity (g) is the gravitational acceleration experienced at the surface of a planet or celestial body. It depends on the body's mass and radius, and determines how much objects weigh on that surface.

2. How Does the Calculator Work?

The calculator uses the surface gravity equation:

Where:

• \( G \) — Gravitational constant (6.67430 × 10⁻¹¹ m³/kg·s²)
• \( M \) — Mass of the planet or celestial body (kg)
• \( r \) — Distance from the center of mass (m)

Explanation: The equation shows that gravity decreases with the square of distance from the center and increases linearly with mass.

3. Importance of Surface Gravity Calculation

Details: Understanding surface gravity is crucial for space missions, planetary science, and determining if a planet can retain an atmosphere or support life as we know it.

4. Using the Calculator

Tips: Enter the gravitational constant (default is Earth's value), planet mass in kilograms, and distance from center in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's Earth's surface gravity?
A: Approximately 9.81 m/s² at sea level, though it varies slightly by location.

Q2: How does gravity change with altitude?
A: Gravity decreases with the square of distance from the planet's center, so higher altitudes experience slightly less gravity.

Q3: Why is G so small in value?
A: The gravitational constant is a fundamental physical constant that reflects the relative weakness of gravity compared to other forces.

Q4: Can this calculate gravity inside a planet?
A: No, this equation only works for points outside a planet's surface. Internal gravity calculations require different formulas.

Q5: What's the surface gravity of Mars?
A: About 3.71 m/s², which is roughly 38% of Earth's gravity.