① Rubber is attached to the surface of the racket to increase the friction between the ball and the racket. ② Table tennis changes direction and speed after being hit, because force can change the motion state of objects. (3) Loop ball means that the rotating ball moves along an arc, because the pressure is low where the air velocity is high. Table tennis will rebound when it falls to the table, because different forms of energy can be transformed into each other. ⑤ The ball still moves forward after it leaves the racket, because it has inertia.

From the aspects of friction, force, pressure and energy conversion.