Question

A sphere of mass of 40 kg is attracted by second sphere of mass 60 kg with F=4×10^-5N. If G=6×10^-11Nm^2Kg^-2. Calculate the distance 2 spheres.
A)3cm
B)6cm
C)9cm
D)10cm

Answer 1

A sphere of mass 40kg is attracted by a second sphere of mass 60kg with a force equal to 4mgf.If G = 6*10^-11 Nm^2kg^-2.calculate the distance between them. Acceleration due to gravity=10ms^-2

Answer 2

We know that gravitational force between two bodies is given by -

F = G m1m2/r²
where m1,m2 are masses of the bodies 
G is Universal gravitation constant.
r is the distance between two objects from their centers.

So here 
F = 2.5 × 10^-6
r = 30mm or 30 × 10^-3 m 
m1 = 40kg
m2 = 80kg 
we have to find the value of G

so plug the values in the formula 

we get 
2.5×10^-6 = G × 80×40/3×10-²

so we get G = 0.0023.. × 10^-8