Abstract: A table tennis ball which has, on the spherical surface thereof, a marking to make a ball rotation measurable. The marking contains a number of marking points, which are distributed on the ball surface in such a way that the standard deviation of the lengths of the orthodromes between each of the marking points and the three nearest neighboring points thereof is at least 12% of the average value of these lengths, and the minimum length of the orthodromes between each of the marking points and the three nearest neighboring points thereof is at least 40% of the average value of these lengths.

Abstract: The trampoline (1) as per the invention is comprised of a frame structure (2) and a jumping mat mounted in the frame structure (2). An arrangement of sensors (8) is provided by means of which forces or accelerations acting on the jumping mat (3) are recorded. The signals of the sensors (8) are read into an evaluation unit (9). Output quantities are generated from the chronological progression of the signals.

Abstract: The trampoline (1) as per the invention is comprised of a frame structure (2) and a jumping mat mounted in the frame structure (2). An arrangement of sensors (8) is provided by means of which forces or accelerations acting on the jumping mat (3) are recorded. The signals of the sensors (8) are read into an evaluation unit (9). Output quantities are generated from the chronological progression of the signals.