A bullet of mass 0.1 kg is shot into the wall and is stopped in 10 cm
If the resistive force acting on the bullet by the wall is 9800N
Estimate the speed of the bullet
Ans
K.E. lost by bullet=W.D. against resisting force
0.5*0.1*v^2=9800*0.1
v=140ms-1
如果我這樣做有問題嗎
Negative workdone by resisting force = lose in KE
-9800*0.1 = 0 - 0.5*0.1*v^2
v= 140
這樣做可以嗎 thx
energy 問題
2007-12-21 4:01 am
回答 (1)
2007-12-21 4:54 am
✔ 最佳答案
第二種方法唔得你第二種已經講明係lose in KE
咁咪即係要+ 如果你係-咁就即係gain in KE
你列 -9800*0.1 = 0 - 0.5*0.1*v^2 logically唔太對
marker有權唔比分 因為你個KE 一定係KE lost
收錄日期: 2021-04-23 17:36:27
原文連結 [永久失效]:
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