Abstract : The report summarizes some results of FY72 research task. The investigation has attempted to provide a basic understanding of plate impacts. Three categories of ballistic effects have been considered, viz., perforation without shatter, perforation with shatter and no perforation with shatter. Expressions are determined for the ballistic limit, residual velocity, shatter velocity, and spray angle. Concepts from nonlinear mechanics and shockwave theory are useful tools in this analysis, and a few nonlinear differential equations have been derived from the projectile's motion. Thus we may speak of Bernoulli nonlinearity and Riccati nonlinearity. Our motivation is for mathematical simplicity with some physical reality and our methods and results can be extended to more general problems of penetration dynamics.