SOLUCIONES / EJERCICIOS PARA PRACTICAR 1. m = 20 kg / F = P = m · g = 20 · 9.8 → F = 196 N S = 800 cm2 → S = 0.08 m2 P=?
P = 2450 Pa 2. m = 40 kg / F = P = m · g = 40 · 9.8 → F = 392 N Cara: 0.6 m x 0.3 m
S = 0.6 · 0.3 = 0.18 m2
P = 2177.8 Pa Cara: 0.6 m x 0.4 m
S = 0.6 · 0.4 = 0.24 m2
P = 1633.3 Pa Cara: 0.3 m x 0.4 m
S = 0.3 · 0.4 = 0.12 m2
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P = 3266.7 Pa 3. P=? m=? S = 1200 cm2 → S = 0.12 m2 P = 500 Pa
F = 0.12 · 500
F = P = 60 N P=m·g 60 = m · 9.8
m = 6.12 kg
4. Spunta = 0.01 mm2 → Spunta = 10-18 m2 F = 100 N
P = 1010 Pa
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S=? m = 200 kg → F = P = m · g → F = 200 · 9.8 = 1960 N P = 106 Pa
S = 1.96 · 10-3 m2
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