如果有個人跳樓 我接唔接得住佢

2009-11-09 7:00 pm
如果有個大約60KG既人起20樓(40 METER) 跳落黎~
落到黎個FORCE有幾大????
如果我用手去接住佢~我隻手會唔會斷???
如果我BEND KNEE會唔會有幫助???

回答 (4)

2009-11-15 4:33 pm
當然會一齊死,因跳落黎產生沖力,壓死你
2009-11-09 8:13 pm
Based on simple physics principles, first find out the velocity of the man before striking the ground.

Use conservation of mechanical energy, the loss of potential energy = gain in kinetic energy
i.e. 60g.(40) = (1/2)(60).v^2
where v is the velocity of the man before striking the ground
hence, v = 28 m/s

Momentum of the man = 60 x 28 Ns = 1680 Ns
Assume you try to catch him with your hand, the contact time is about 0.5 second, the force F given to your hand is

(F - 60g).(0.5) = 1680 (impulse = change of momentum)
i.e. F = 3960 N = 396 kgf, which is about 6.6 times the body weight of the man

Such force is large enough to break your arms.

If you attempt to reduce the impact by bending knees. assume such action lengthen the impact time to 1 sec., the force now becomes

F = (1680 +60g) N = 2280 N = 228 kgf, about 3.8 times the body weight of the man. You cannot sustain such weight.
2009-11-09 8:10 pm
力量有多大,沒算空氣阻力吧!若沒算,我就可以算給你看.....
2009-11-09 7:06 pm
如果你瘦人地肥,咁你同佢一定齊齊出事,你會手斷,人地又會掉下去


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