(3 points) As shown in the picture, the cartoon depicts the scene where monkeys and rabbits share radishes. Who really got the radish? Three students from Yuhong Middle School in Texas asked.

( 1)A； (2) Wrong, use the spring dynamometer to pull it down obliquely, and compare the size of "force × the distance from the point of force action to the fulcrum and resistance× the distance from the point of resistance action to the fulcrum".

Test and analysis: (1) The balance condition of lever is: power multiplied by power arm equals resistance multiplied by resistance arm. As can be seen from Figure 26, Figure A meets the meaning of the question; (2) The balance condition of lever is that force times arm equals resistance times arm, so it is wrong to draw the conclusion that "force × distance from the point of force action to fulcrum = resistance× distance from the point of resistance action to fulcrum". The reason why students come to the wrong conclusion is that the pulling direction of the spring dynamometer is perpendicular to the lever, and the size of the arm of force is equal to the distance from the fulcrum to the point of force action. Therefore, in order to verify the balance condition of the lever, the spring dynamometer is used to pull down obliquely, and the size of "force × the distance from the point of force action to the fulcrum and resistance× the distance from the point of resistance action to the fulcrum" is compared.