This video is an excerpt from "Hidden By Time: Seeing the Physical World with High-Speed Cameras," an educational DVD from Physics Curriculum & Instruction.
www.PhysicsCurriculum.com/hidd...
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Racquet Impacting Tennisball & Racquetball:
Camera Imaging: 2000 frames/sec
Playback: 1.1 frames/sec
Slow Motion Factor: 1818
The 1st segment shows a racquet hitting a tennis ball, the flattening of the ball is clearly seen. The racquet is in contact with the ball for a total time of 0.004 seconds.
A racquet impacting a racquetball is shown in the 2nd segment. The racquetball flattens dramatically with a dimple appearing as the ball regains its shape. The racquetball's total contact time with the racquet is 0.005 seconds.
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Impact of Racquetball
Camera Imaging: 2000 frames/sec
Playback: 2 frames/sec
Slow Motion Factor: 1000
Driven downward by a racquet at a high velocity, a racquetball undergoes dramatic deformation as it impacts a hard surface.
The 1st segment shows the case of the racquetball making a glancing impact with the surface. The 2nd segment shows the racquetball impacting the surfacing from directly overhead. Finally, the 3rd segment shows the racquetball impacting the corner of a concrete block.
Seen with the naked eye, the contact time between ball and surface of 0.005 seconds makes it difficult to pinpoint where the ball struck the surface, as a streak of blue is all that is perceived. The high-speed camera reveals the entire impact sequence: the flattening of the ball, the formation of a dimple, the elongation, and the rebound in which the ball pulsates for 0.007 seconds after impact.