本题目来源于试卷: 美国2021年物理杯赛真题 PHYSICS BOWL 2021，类别为 美国物理杯赛(Physics Bowl)
[单选题]
Two balloons are charged identically and uniformlyby rubbing them with wool. One is placed on a scalewhich is then tared. No charge is transferred to thescale. The other is then placed above it separated by30 cm. The scale reads 0.32 grams. What is theclosest estimate for the charge on each balloon?
A. 200 C
B. 200 mC
C. 200 μC
D. 200 nC
E. 200 pC
参考答案: D
本题详细解析:
$F=\frac{KQ^2}{R^2}=177nC$
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