Work out gravitational field strength instantly with clear inputs, formula shown and shareable results.
Field strength is GM/r^2, the acceleration a test mass would feel. Earth's mass at its mean radius gives 9.82 m/s2, matching measured surface gravity. The same numbers give escape velocity sqrt(2GM/r) - 11.2 km/s for Earth - and the circular orbital speed, which is smaller by a factor of sqrt2 at 7.9 km/s.
Field strength
g = G M / r^2
Escape and orbital speed
v(escape) = sqrt(2GM/r); v(orbit) = sqrt(GM/r)
About 11.2 km/s from the surface, ignoring atmospheric drag and the rotation of the launch site.
Escaping needs enough kinetic energy to cancel the whole potential well, which is twice the energy of a circular orbit at the same radius.