力和物体的平衡(一)(国外英文资料).docVIP

力和物体的平衡(一)(国外英文资料) Balance of force and object (1) The common bicycle, the front wheel is the wheel, the rear wheel is the active wheel (the cyclist pedals the pedals, and the rear wheels are driven by the gear and the chain). When the bicycle is running, the wheels will only roll with the ground and not slide. When driving bike in the horizontal plane, a front wheel friction for f1, rear wheel by the force of friction is f2, the direction of friction of the two is right () The direction of A, f1 and f2 is the opposite of the direction of the car B, f1 and f2 are in the same direction as the car C, f1 and car move in the opposite direction, f2 is the same direction as the car D, f1 and car move in the same direction, and f2 moves in the opposite direction The national college entrance examination questions, 2 (1994), as shown in the figure is C level ground, A and B are the two rectangle blocks, F is forces acting on B along the horizontal direction, object A and B at the same rate as uniform linear motion. Therefore, friction factor between A and B mu mu kinetic friction factor between 1 and B and C 2 is likely to be () A, mu 1 is 0, mu 2 is 0, mu 1 is 0, mu 2 is not 0 C, mu 1 is not equal to 0, mu 2 is 0 D, mu 1 is not 0, mu 2 is not 0 3 G, put a heavy object, with a horizontal thrust F = kt (k is constant, t for time) pressure on the metope of vertical high enough, since t = 0 objects by friction with the changes of t F is which one in the picture? () 4, with five force acting on the particle P at the same time, their size and direction of two adjacent side of hexagon and three diagonals, as shown in figure, the composition of the five forces is equal to one of the smallest force () A, three times B, four times C, five times D, six times 5, as shown, AB is a diameter of semicircle, AO = OB, point P is a point on the circumference of a circle, at point P work three concurrent force, size of F1, F2 and F3, respectively, their combined size of () A, 3F2 B, F1, F2 +