Segment V3.1: Balancing Ball

(Related to Textbook Section 3.2 - F=ma Along a Streamline)

According to the Bernoulli equation, an increase in velocity can cause a decrease in pressure.

The table tennis ball is supported by a jet of air. The net vertical air force is balanced by the ball's weight. If the ball is displaced from the center of the jet, the air velocity past the ball is greater on the side near the jet's center than it is on the side near the jet's edge. Thus, the pressure on the ball is lower near the center, and the ball returns to its stable equilibrium position centered in the air jet.