摘要 |
<p>The stiffness of a tennis racket is adjusted so that the first mode of bending of the racket under free-free constraint conditions is between 170 Hz and 250 Hz preferably between 200 Hz and 210 Hz. The second mode of bending under clamped-free constraint conditions is between 215 Hz and 315 Hz and preferably between 230 Hz and 265 Hz.</p> |