Răspuns:
Explicație:
greutatea este F=G_planeta = mg_planeta unde g_planeta = acceleratia gravitationala.
F = (k*M_planeta*m)/R^2
k = constanta gravitationala,
M_planeta = masa planetei
m = masa cosmonautului
R = raza planetei respective
m*g_planeta = (k*M_planeta*m)/R_planeta^2 => g_planeta = (k*M_planeta)/R_planeta^2
M_planeta = M_pamant /9
R_planeta = R_pamant /4
g_planeta = (k*M_pamant/9)/(R_pamant/4)^2 = (k*M_pamant/9)/(R^2)/16 = (1.77 k*m)/R^2 = 1.77*g
greutatea cosmonautului va fi:
G_planeta = m*g_planeta = m * 1.77*g = 80 kg * 1.77 * 9.8 N/kg = 1393.7 N