Tennis Racket

Shop Head Tennis Racquets here: www.the-tennis-store.com Novak Djokovic talks about his Head Speed tennis racquet, the Speed Pro. He’s into the 2011 Australian open final with it. Specs: Color White Head Size 98 Strung Weight 12.5 Length 27″ (68.6 cm) Cross Section 22 mm Balance 8.8 pts head light Swing Weight 345 Stiffness 70 String Pattern 16m x 19c Tension Range (lbs) 52-62 lbs Grip Type Leather Technology Head Teflon Grommets, Head Youtek Swing Style Very Long / Fastest Racquet Cover Included? No

A fascinating observation about the rotation of a tennis racket (or ping-pong paddle) is that the racket flips over if rotated freely about one of its primary axes. This is a result of Euler’s Equations of Motion and the moments of inertia about the various axes being time-independent. The so-called “Tennis Racket Theorem” applies to the case where the moments of inertia about the principal axes are spaced: I1 ≪ I2 ≪ I3. The theorem states that rotations about axes #l and #3 are much more stable than about axis #2, even though I2 may be very close to I3 in value.