This paper presents a high accuracy method to measure gravitational acceleration in an undergraduate
laboratory program. The experiment is based on water in a cylindrical vessel rotating about its
vertical axis at a constant speed. The water surface forms a paraboloid whose focal length is
related to rotational period and gravitational acceleration. This experimental setup avoids
classical source errors in determining the local value of gravitational acceleration, so prevalent
in the common simple pendulum and inclined plane experiments. The presented method combines multiple
physics concepts such as kinematics, classical mechanics and geometric optics, offering the
opportunity for lateral as well as project-based learning.