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]
A brick is moving at a kzatz2(jic5( +wgvfg: -lbdyr ea ,8*speed of $3\:m/s$ and a pebble is moving at a speed of $5\:m/s$. If both objects have the same kinetic energy, what is the ratio of the brick's mass to the pebble's mass?
A. 25:9
B. 5:3
C. 4:1
D. 3:1
E. $\sqrt{5} / \sqrt{3}$
参考答案: A
本题详细解析:
KE=$\frac{1}{2} mv^2$. the mass ratio is based upon the ratio of the squares of the velocities.
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