在圖中，杠桿在力F1和F2的作用下處于靜止?fàn)顟B(tài)，l2是力F2的力臂。請(qǐng)?jiān)趫D中畫出F1的力臂l1和力F2。
答案見解析。

試題分析：動(dòng)力臂是支點(diǎn)到動(dòng)力作用線的距離。阻力臂是支點(diǎn)到阻力作用線的距離。根據(jù)要求準(zhǔn)確地畫出力臂。
點(diǎn)評(píng)：了解動(dòng)力臂和阻力臂的畫法是作圖的前提。
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