Question

please help me to calculate this. need urgently please...

Answer 1

dear put f=mg n then the equation becomes g=Gm/ r*r and then u can solve it n it's r*r not d*d

Answer 2

F(g) = Gm₁m₂/(d)²

F(g) = m x a(g)

where a(g) = acceleration due to gravity

and F(g) = gravitational force

a(g) = F(g)/m₂

a(g) =  Gm₁m₂/(d)² x m₂

a(g) = Gm₁/(d)₂

a(g) = 6.67 x 10⁻¹¹ x 5.9 x 10²⁴ / 64 x 10² x 10³ x 64 x 10² x 10³

a(g) = (6.67/64 x 64) 5.9 x 10⁽²⁴⁻¹¹⁻²⁻³⁻²⁻³⁾

a(g) = 0.00162 x 5.9 x 10³

a(g) = 0.009607 x 10³ 

a(g) = 9.60 ≈9.8 m/s²

Difference came here as we tookdistance of earth from centre to surface 
6400 km =6.4 x 10⁶  m