Gravitational Force of Three Identical Masses

[PSEYE]

Homework Statement

Three identical masses of 550 each are placed on the x axis. One mass is at X1= -10.0 , one is at the origin, and one is at X2= 43.0 .
What is the magnitude of the net gravitational force on the mass at the origin due to the other two masses?

G = 6.673 x 10-11

Homework Equations

I'm using just the regular force of grav.

F_grav= GMm/R^2

Net force:
F_net= F1-F2

and I tried Gm^2(1/X1^2-1/X2^2)

I'm getting logical numbers, but they're not right.

I calculated Force1 to be -0.00202
I calculated Force2 to be 0.00109

I think I may have squared the mass to get the these numbers...what do I do with the masses? there are three of them, do I use 1650? or 550?

 

[PSEYE]

got it

 

[baba89]

I would like to clarify a few things about the given problem. Firstly, the given information does not specify the units for the masses (550 what? grams, kilograms, etc.) so it is important to clarify this in order to accurately calculate the gravitational force. Secondly, the given equation for gravitational force (F_grav = GMm/R^2) is incorrect as it does not take into account the distance between the masses. The correct equation should be F_grav = Gm1m2/R^2, where m1 and m2 are the masses and R is the distance between them.

Now, to calculate the net gravitational force on the mass at the origin, we need to consider the gravitational forces exerted by both the masses at X1 and X2. Since all three masses are identical, we can simply calculate the force exerted by one mass and multiply it by 3.

Using the correct equation, we can calculate the force exerted by the mass at X1 on the mass at the origin as F1 = (6.673 x 10^-11)(550)^2/(10)^2 = 0.0015125 N. Similarly, the force exerted by the mass at X2 on the mass at the origin is F2 = (6.673 x 10^-11)(550)^2/(43)^2 = 0.0001251 N.

Therefore, the net gravitational force on the mass at the origin is F_net = (3)(0.0015125) - (0.0001251) = 0.0044124 N.

In conclusion, it is important to use the correct equation and consider the distances between the masses when calculating gravitational force. Also, it is important to specify the units for the masses in order to accurately calculate the force.