Hotel table rolling

Install ball bearings in the turntable, and replace sliding friction with rolling friction; Belonging to reducing friction;

(2) The gravity of an object resting on a horizontal plane is the pressure at this time. If the child wants to play with the turntable table, he will push the turntable horizontally, and the rotation speed of the turntable will be obviously accelerated, but the friction between the turntable and the big desktop remains unchanged.

(3) With the increase of dishes placed on the movable table, the quality of the desktop is increasing, so it can be seen that its gravity is also increasing. At this time, the gravity of the object resting on the horizontal plane is the pressure. It can be seen that its pressure is increasing, and when the contact surface is rough, increasing the pressure can increase the friction, so with the increase of dishes placed on the movable table, the rotational sensitivity of the movable table is obviously reduced.

So the answer is: rolling instead of sliding, unchanged, increasing pressure and increasing friction.