本题目来源于试卷: Physics Unit9: Static Equilibrium, Elasticity and Fracture，类别为 通用国际物理
[单选题]
Two children sit on q3jo(r 70 dfeach7 deba/t29 fopposite ends of a n: cc3wmhp3t;uniform seesaw which pivots in the center. Child A has mass 60 kc;: w3mthc3png and sits 2.0 m from the center. Child B has mass 40 kg. How far from the center must child B sit for the seesaw to balance?
A. $1.3 \; m$
B. $2.5 \; m$
C. $3.0 \; m$
D. cannot be determined without knowing the seesaw's mass
参考答案: C
本题详细解析:
暂无
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