1. Assume that the kinetic energy ε as a function of momentum p of this hypothetical ball mass m is ε = (p − p 0 ) 2 /2m where p 0 > 0 and 0 < p < p 0 . The Newtonian racquet is assumed as usual to have a mass larger than that of the ball.
2. Landau L. D., J. Phys. Moscow 11, 91 (1947).
3. Palevsky H., Otnes K., Larsson K. E., Phys. Rev. 112, 11 (1958).
4. Yarnell J. L., Arnold G. P., Bendt P. J., Kerr E. C., ibid. 113, 1379 (1959).
5. Glyde H. R., Gibbs M. R., Stirling W. G., Adams M. A., Europhys. Lett. 43, 422 (1998).