An Estimate of the Effect of Back Spin on the Critical Angle in the Unyawed Ricochet of a Cylinder

A method is described for giving an estimate of the effect of back spin on the critical angle for the ricochet of a cylinder off water. The method incorporates both the spin and the weight of the projectile into the Birkhoff et al theory, as described by Johnson and Reid (1) ‖ for a sphere. The differences and predictions concerning hydrodynamic pressure and lift, etc., are compared with those made by several other authors. A comparison of our new results with some available experimental results has also been made.