Question

A 20 kg sphere is at the origin. A 10 kg sphere is at (x,y) = (-30cm,0cm) and a 30 kg sphere is at (0cm,40cm). Calculate the gravitational force on the 10 kg sphere, resulting from the other two spheres.

Please help! Thanks

Answer 1

The 10 kg sphere has a force directed +x direction of G(20*20)/.3^1
the 10 kg sphere has a force directed upward to the right of G10*20/.5^2 (3,4,5 triangle)

so this is a vector problem. first, find the components of the second force:
secondForce=G10*20/.5^2 *((4/5)j +(3/5)i)

so in the x direction:G200/.25*4/5+G200/.3^2
in the y direction: G200/.5^2 * 3/5

do determine those.
net force=sqrt(Fx^2 + Fy^2)
a bit of algebra will be needed.