Uniform Circular Motion/Law of Gravitational Problem need help badly

Question

anonymous · Answer

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anonymous · Answer

GG PHY10 waa ang hirap haha

anonymous · Answer

First think broadly (conceptually).  Which side of A do you think you would need a mass in order to produce a gravitational force on A which would counter act (balance) the gravitational forces on A caused by B and C? 

Next you must calculate.  I would analyze the forces acting on A with a free body diagram (you only are asked to find Fnet= 0 for particle A (that is what "no net gravitational force" is saying).  Force of gravity on A caused by B is in the +y direction and the force of gravity on A caused by C is in the -x direction.  You must create a gravitational force (by choosing where to place your D mass (4.00ma) that will simultaneously cancel our those two forces (hint: the force of gravity on A caused by D will have both x and y components).

Hope that helps.

mrnood · Answer

you can treat the x and y component separately

the x force of the new mass will be 4m/x^2  (where x is its x coordinate)

this has to cancel the force from particle c (=3m/1.5^2) so you can solve for x

do the same for y