FLOATING PINGPONG In this experiment the air moves

FLOATING PING-PONG In this experiment, the air moves faster at the center of the flow produced by the blow, making the pressure at this point always lower. The ball is always kept in the center of the air jet because it is pushed there by the slower air and, therefore, by the greater pressure of the surrounding air. At the same time, the ball remains in suspension since the force exerted by the rising air jet is sufficient to balance its weight. Materials: Hair dryer; Table tennis ball; Toilet paper tube. How: Switch on the hairdryer in the cold air version; Turn the dryer mouth upwards; Place the ping-pong ball in the air column; Gently move the direction of the air blowing for the ball to follow this flow; Try placing an empty toilet paper tube at the airflow outlet. • The ball is constantly spinning as the air passes through its faces at different speeds. If you try to make some drawings on the ball, this effect will be easier to observe. • The ball floats at the point where the force of air flow from the dryer and the force of gravity match. Air pressure keeps the ball in the air flow, even when the dryer is tilted, because the air passes quickly through the ball, keeping it in place and making it spin. • When using a roll of toilet paper, air is pushed through a smaller space. This causes the air to move faster, the ball to float higher and spin faster.