Velocity of the fragments produced by oblique impact cratering experiments on gypsum

Abstract

Nylon spheres of 7mm in diameter were shot on gypsum targets at the impact velocity of 4.3km/sec. Two or three dimensional velocity vector, time of the ejection and mass were measured and/or estimated for each fragment by use of high-speed video cameras. Fragments are classified into two groups as earlier fragment group and later fragments group. The earlier group has almost the same mass-velocity distribution as one in Nakamura and Fujiwara (1991) obtained for disruptive event. The later fragments group, which only be seen in cratering event, consists of numbers of slow and small fragments, ejected normal to the target surface.