1, put the same number of pieces on both sides; 2. Put plastic bags on the left and right sides of the bamboo pole with the same scale; 3. Put three pieces (3×4÷4)4. Put two pieces (6×1÷ 3); The product of the number of pieces on the left and right sides should be equal to the number of scales; 5. Research purposes Put three pieces on the left scale 4 and keep them unchanged. ② Record the experimental results. Specific activities: the number of pieces placed on the right scale 1 2 3 4 6 12 6 4 3 2 product 6. The lever principle of extra-curricular links in 5438+02121212 is also called "lever balance condition". In order to balance the lever, the magnitude of two forces (force point, lever principle fulcrum and resistance point) acting on the lever is inversely proportional to its force arm. Power× power arm = resistance× resistance arm, which is expressed as F 1? 6? 1 l 1=F2？ 6? 1l2. Where F 1 stands for power, l 1 stands for power arm, F2 stands for resistance, and l2 stands for resistance arm. As can be seen from the above formula, in order to balance the lever, the power arm is several times that of the resistance arm, and the power is a fraction of the resistance.