Description: Name: walking wire Learning content:Understand what is the focus and understand the changes in focus and pivot. The center of gravity is the point at which the resultant force of the gravity of all the constituent points in the gravity field passes when the object is in any orientation. The center of gravity of a regular, uniform density object is its geometric center. Center of gravity of an irregular object can be determined by the suspension method. The center of gravity of the object is not necessarily on the object. In addition, the center of gravity can refer to the center or main part of the matter. Introduction: We sucked four magnets into the symmetrical parts of the two legs of the model, attached the cotton thread to the suction cup, and then sucked the suction cup on the smooth glass surface, tightening the cotton thread with one hand and placing the model On the legs with one hand. Cotton line; adjust the cotton line up and down, look! Our can walk the tightrope! Let children learn some intellectual and chemical enlightenment while playing, and help them learn better. Package details: 1* walking tightrope