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1.C 2.D 3.A 4.A 5.A 6.左向下偏右(提示:由原文图可知,轮子下部向左凸出,说明地面对右后轮的摩擦力方向向左,汽车正在向左转弯.地面对右后轮的作用力方向为向上偏左.根据力的相互作用规律,右后轮对地面作用力的方向为向下偏右)7.迫使湿衣服里面的水从衣服纤维之间的缝隙高速喷出.利用高速水流将灰尘冲洗掉8.AOD 9.(1)骑不走(2)停不下来10.200东变大不变11.(1)二力平衡(2)不对没有控制接触面的粗糙程度相同(3)表略.(4)当压力大小一定时,接触面越粗糙.摩擦力就越大
1.C 2.D 3.A 4.A 5.A 6. To the left and down to the right (hint: from the original figure shows that the lower part of the wheel is protruding to the left, indicating that the friction of the ground on the right rear wheel is toward the left The car is turning to the left. The direction of the force acting on the right rear wheel is upward and leftward. According to the interaction law of force, the direction of the right rear wheel to the ground is downwards to the right. 7. Forcing the wet clothes inside The water is sprayed at a high speed from the gap between the clothes fibers. Dust is washed away with high-speed water 8.AOD 9. (1) Can’t go without riding (2) Can’t stop 10.200 The east is getting bigger unchanged 11. (1) Two forces The balance (2) does not have the same degree of roughness of the uncontrolled contact surface (3) Table is omitted. (4) When the pressure is constant, the rougher the contact surface, the greater the friction force.