Dynamics of a sphere launched vertically in water

To investigate the dynamics of a sphere's motion and the behavior of the air–water interface induced by the sphere, a solid sphere is launched vertically upward in water toward the air–water interface. Four spheres with different densities ρp were studied: Sphere A (ρp = 7930kg/m3), Sphere B (ρp = 3900kg/m3), Sphere C (ρp = 2180kg/m3), and Sphere D (ρp = 1360kg/m3). By experimentally visualizing the sphere motion in water, their launch velocity can be set with high accuracy. When a sphere passes through the air–water interface, it makes the interface more complex and entrains water. Additionally, spheres with a small value of ρp were demonstrated to not always vertically collide with the air–water interface; as a result, different behaviors of spheres can be observed in the air. •A solid sphere is launched vertically upward in water toward the air–water interface.•Investigation the dynamics of a sphere's motion and the behavior of the air–water interface induced by the sphere.•Four spheres with different densities were studied for comparison.•When a sphere passes through the air–water interface, it makes the interface more complex and entrains water.•Spheres with a small density were demonstrated to not always vertically collide with the air–water interface. [Display omitted]