Planets are not uniform inside. Normally, they are densest at the center and have decreasing density outward toward the surface. Model a spherically symmetric planet, with the same radius as the earth, as having a density that decreases linearly with distance from the center. Let the density be 1.9010⁴ kg/m³ at the center and 2900 kg/m³ at the surface.

What is the acceleration due to gravity at the surface of this planet? Express your answer in meters per second squared.