physic 難題 一
2011-12-13 8:12 pm
回答 (1)
2011-12-13 8:55 pm
✔ 最佳答案
Q7. option Dsince potential energy is propotional to height.
Q9. Use conservation of momentum
momentum of train = 8x10^4 x 10/3.6 kg-m/s = 222000 kg.m/s
hence, 222000 = 100v
where v is the speed of ejection of water
i.e. v = 2220 m/s
The answer is option G
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