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Meilleure réponse !
2014-05-30T12:36:21+02:00
Exercice 1
1) F = (G x M xm) : d²
G = 6,67x10^-11 Nxm²/kg² (^ se lit puissance)
M (masse de la terre) = 5,97 x 10^24 kg
m (masse de la lune) = 7,34 x 10^22 kg
d (distance Terre-Lune) = 384 000 km = 3,84 x 10^5 km = 3,84 x 10^5 x10^3 = 3,84 x 10^8 m

F = (6,67x10^-11 x 5,97 x 10^24 x 7,34 x 10^22) : (3,84 x 10^8)²
F = (6,67 x 5.97 x 7.34 x 10^(-11+24+22)) : (3.84² x (10^8)²
F = (292.3 x 10^35) : (14.75 x 10^(8x2))
F = (292.3 x 10^35) : (14.75 x 10^16)
F = (292.3 x 10^35 x 10^-16) : 14.75
F = 292.3 x 10^(35-16) : 14.75
F = 19,82 x 10^19

2)  F = (G x M xm) : d²
G = 6,67x10^-11 Nxm²/kg²
M (masse de la trousse) = 420 g = 0,42 kg = 4,2 x 10^-1 kg
m (masse du stylo) = 10 g = 10^-2 kg
d (distance trousse-stylo) = 20 cm = 2x 10^-1 m

F = (6,67x10^-11 x 4,2x10^-1 x 10^-2 ):(6,67x10^-11)²
F = 28.014 x10^-14 :(44,49 x 10^-22)
F = 0.6297 x10^-14 x 10^22
F = 6.3 x 10^8

3)  F = (G x M xm) : d²
G = 6,67x10^-11 Nxm²/kg²
M (masse du soleil) = 1.98 x 10^30 kg
m (masse de mars) = 642 x 10^21 kg
d (distance soleil-mars) = 228 x 10^6 km = 228 x 10^6 x10^3 = 228 x 10^9 m

F = (6,67x10^-11 x 1.98 x 10^30 x 642 x 10^21):(228 x 10^9)²
F = (6,67 x 1.98 x 642 x 10^40):(51984 x 10^18)
F = 0.16 x 10^(40-18)
F = 1.6 x 10^21

Exercice 2
1.
D = 2 pi x 1,427 x 10^12 km = 2.854 Pi x 10^12 km = 2.854 Pi x 10^17 m
T = 30 ans

V = D/T
V = 2.854 Pi x 10^12 / (30x365x24)
V = 2.854 Pi x 10^12 / 262800
V = 3,41 x 10^-5 x 10^12
V = 3.41 x 10^7 km/h

v = 3,41 x 10^-5 x 10^17 / 3600
V = 9,47 x 10^-4 x 10^12
V = 9,47 x 10^8 m/s

2. V = 170640 km/h
T = 88j = 88x365x24 = 770880 h
D = vT = 170640 x 770880 = 131542963200 km
D = 2Pi r
d'où
r = D /2Pi
r = 131542963200/2Pi
r = 41 871 425 644 km