Understanding gravity & escape velocity
Build a world and calculate its gravitational pull, your weight, and its escape speed.
The idea behind it
A planet’s mass increases its pull, while a larger radius puts its surface farther from the center. Your mass stays the same on another world; your weight, a force measured in newtons, changes.
The relationship to remember
At 1 Earth masses and 1 Earth radii: weight = 70 kg × 9.82 m/s² = 687.42 N.
Make your own discovery
Double the radius while keeping the mass fixed. Surface gravity falls to one quarter of its original value.
Try the interactive lab ↗What this model leaves out
A spherical, non-rotating body without atmospheric drag. Radius means distance from the center to the reference surface. Gas giants do not have a solid surface to stand on.
Check your understanding
What is the difference between mass and weight?
Mass measures the amount of matter in kilograms. Weight is gravitational force, measured in newtons.
Does escape speed depend on spacecraft mass?
In this ideal model, no. It depends on the attracting world’s mass and the starting distance from its center.
Continue with the formula reference or test yourself in space practice.