Respostas

2013-08-23T17:40:50-03:00
Energia Cinetica do Trem:

10T = 10.000Kg

72km/h = 20m/s

Ec = 10.000 * 20m/s

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Ec = 200.000 Joules
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0,8km = 800m

Epe = K*x²/2
200.000 = K * (800)² / 2

400.000 = K * 640.000

400/640 = K

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K = 0,625N/m
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